ersatztv/docs/decisions.md

# Decisions — append-only log

Purpose: why the codebase does what it does, so agents don't "fix" an established convention or
relitigate a settled call. Append new entries at the bottom in date order (plus a TOC line in the
Index); **update this doc in the same PR that changes any fact below** (or that establishes a new
convention worth recording).

**Append-only, enforced (ersatztv#303 H9).** A commit or PR that *deletes or modifies* an existing
line is blocked by the Husky `commit-msg` hook and the CI `decisions-guard` job; insertions anywhere
are always allowed. The block is lifted only by the **`[decisions-edit]`** token in the commit
message, for the two legitimate reasons to touch history:
- **Fix a factual error** in a past entry.
- **Supersede a reversed decision** — add the new dated entry, then prepend a
  `> **Superseded YYYY-MM by <new entry title>.**` banner to the old entry and tag its Index line
  `(superseded)`. Keep the old entry — *why we changed our mind* is the point; never silently rewrite it.

**Consolidation** (prune/merge superseded entries, refresh the Index) is primarily a step in the
release checklist (`docs/ci-cd.md` → Versioning & releases), done at each release/milestone with
`[decisions-edit]` — not ad hoc mid-arc. A **size floor** backstops it between releases: the
`decisions-guard` CI job warns (non-blocking) once this file exceeds **1800 lines** — the point where
it no longer fits one default 2000-line agent Read — so append-only can't grow past what an agent can
read in a pass. The metric is the file's read cost (line count), not the entry count. Together these
keep append-only from accreting stale, contradictory, or unreadably-large history.

---

## Index

Decisions are split between the chronological log **in this file** and four **topic files** under
`docs/decisions/` — large same-topic clusters extracted at the v26.9.0 consolidation (full
rationale preserved). Check the relevant topic file below for its subject; otherwise scan the
in-file entries.

**Topic files:**

- [`decisions/optimistic-concurrency.md`](decisions/optimistic-concurrency.md) — ETag / If-Match / `Version` optimistic concurrency (#253, #259, #265, #269). Mechanics: `api-conventions.md` §7a–§7c.
- [`decisions/api-auth-security.md`](decisions/api-auth-security.md) — API/SPA auth & security posture (#197 bundles + #279 headers, #206, #283, #292, #295, #301, #319, #330).
- [`decisions/release-ci-governance.md`](decisions/release-ci-governance.md) — release / CI / merge governance (#303 H3/H4/H5/H6/H9/H10, #311, #314, #315, #335).
- [`decisions/spa-modularization.md`](decisions/spa-modularization.md) — App.tsx screen/shell extraction epic #243 (#244, #245, #247).

**In this file:**

- [2026-06 — REST API wraps existing MediatR handlers 1:1, no service layer](#2026-06--rest-api-wraps-existing-mediatr-handlers-11-no-service-layer)
- [2026-06 — UI rebuild is a React SPA (ChicoryTV) on the REST API, not a Blazor reskin](#2026-06--ui-rebuild-is-a-react-spa-chicorytv-on-the-rest-api-not-a-blazor-reskin)
- [2026-07 — Response DTOs live in `ErsatzTV.Core/Api`, file-scoped `#nullable enable`](#2026-07--response-dtos-live-in-ersatztvcoreapi-file-scoped-nullable-enable)
- [2026-07 — PUT-replace list endpoints derive `Index` from array order; alternate-schedules last row = catch-all default](#2026-07--put-replace-list-endpoints-derive-index-from-array-order-alternate-schedules-last-row--catch-all-default)
- [2026-07 — Templates editor in the SPA is a table, not Blazor's drag-calendar](#2026-07--templates-editor-in-the-spa-is-a-table-not-blazors-drag-calendar)
- [2026-07-07 — API artwork contract: rooted URLs produced server-side](#2026-07-07--api-artwork-contract-rooted-urls-produced-server-side)
- [2026-07-07 — Decode-style endpoints take a row id and look up server-side](#2026-07-07--decode-style-endpoints-take-a-row-id-and-look-up-server-side)
- [2026-07-07 — Season/episode/music-video drill-in via `parentId`, not new child-listing endpoints](#2026-07-07--seasonepisodemusic-video-drill-in-via-parentid-not-new-child-listing-endpoints)
- [2026-07-07 — Convention docs read at session start, updated in-PR](#2026-07-07--convention-docs-read-at-session-start-updated-in-pr)
- [2026-07-09 — Playback-troubleshooting completion feedback: poll status, no push channel](#2026-07-09--playback-troubleshooting-completion-feedback-poll-status-no-push-channel)
- [2026-07-09 — datetime-local instead of Chronic natural-language start parsing](#2026-07-09--datetime-local-instead-of-chronic-natural-language-start-parsing)
- [2026-07-09 — SPA gates Download Media Sample while a session is active](#2026-07-09--spa-gates-download-media-sample-while-a-session-is-active)
- [2026-07-09 — OpenAPI spec mirrors the runtime Newtonsoft serializer (#198)](#2026-07-09--openapi-spec-mirrors-the-runtime-newtonsoft-serializer-198)
- [2026-07-09 — YAML playout validator: paste-textarea instead of a server file path](#2026-07-09--yaml-playout-validator-paste-textarea-instead-of-a-server-file-path)
- [2026-07-09 — Channel numbers: prompt-driven sequential renumber instead of drag-to-reorder](#2026-07-09--channel-numbers-prompt-driven-sequential-renumber-instead-of-drag-to-reorder)
- [2026-07-09 — "Table, not calendar" convention also covers the deco-templates editor](#2026-07-09--table-not-calendar-convention-also-covers-the-deco-templates-editor)
- [2026-07-11 — Trash "See all" reuses library-browse paging; search stays capped per kind (#213)](#2026-07-11--trash-see-all-reuses-library-browse-paging-search-stays-capped-per-kind-213)
- [2026-07-11 — Logs page-size is a client-local preference, not a server ConfigElement](#2026-07-11--logs-page-size-is-a-client-local-preference-not-a-server-configelement)
- [2026-07-11 — Logs column sorting: allow-listed `sortField`/`sortDirection` on `GET /api/logs`](#2026-07-11--logs-column-sorting-allow-listed-sortfieldsortdirection-on-get-apilogs)
- [2026-07-09 — Per-playout "Schedule reset" button dropped; Reset uses the server-default build mode](#2026-07-09--per-playout-schedule-reset-button-dropped-reset-uses-the-server-default-build-mode)
- [2026-07-09 — Collection custom order: move up/down buttons, any-kind collections](#2026-07-09--collection-custom-order-move-updown-buttons-any-kind-collections)
- [2026-07-10 — Shared "Add to…" layer lives in `web/src/media/addTo/`; select-mode is an explicit toggle](#2026-07-10--shared-add-to-layer-lives-in-websrcmediaaddto-select-mode-is-an-explicit-toggle)
- [2026-07-10 — Schedule-item GET returns a flat, non-polymorphic DTO (`ScheduleItemResponseModel`)](#2026-07-10--schedule-item-get-returns-a-flat-non-polymorphic-dto-scheduleitemresponsemodel)
- [2026-07-10 — Playout API mutations return 409 while the build lock is held (#215)](#2026-07-10--playout-api-mutations-return-409-while-the-build-lock-is-held-215)
- [2026-07-11 — Schedules SPA editor: draft/explicit-Save over instant-persist; Copy includes multi/smart/rerun; shuffled-GET normalization preserved](#2026-07-11--schedules-spa-editor-draftexplicit-save-over-instant-persist-copy-includes-multismartrerun-shuffled-get-normalization-preserved)
- [2026-07-11 — Channel editor: bare-create entry point + external-logo mutual exclusion (#212)](#2026-07-11--channel-editor-bare-create-entry-point--external-logo-mutual-exclusion-212)
- [2026-07-11 — Queue state lives in the pinned Gitea tracker (#237), not in the handoff file](#2026-07-11--queue-state-lives-in-the-pinned-gitea-tracker-237-not-in-the-handoff-file)
- [2026-07-11 — EntityLocker: atomic flags + single-owner release discipline, no owner tokens (#231)](#2026-07-11--entitylocker-atomic-flags--single-owner-release-discipline-no-owner-tokens-231)
- [2026-07-11 — Media-source management REST write API + SPA (#202)](#2026-07-11--media-source-management-rest-write-api--spa-202)
- [2026-07-11 — Legacy→SPA redirect matcher: exact map + ordered segment-template patterns (#204)](#2026-07-11--legacyspa-redirect-matcher-exact-map--ordered-segment-template-patterns-204)
- [2026-07-11 — Pre-removal Blazor rollback tag `blazor-final` (#205)](#2026-07-11--pre-removal-blazor-rollback-tag-blazor-final-205)
- [2026-07-11 — Async-op API contract normalization + playout build observability + F9 scan endpoints (#235)](#2026-07-11--async-op-api-contract-normalization--playout-build-observability--f9-scan-endpoints-235)
- [2026-07-11 — Post-commit side effects run on `CancellationToken.None` (generalized from #251 to #254)](#2026-07-11--post-commit-side-effects-run-on-cancellationtokennone-generalized-from-251-to-254)
- [2026-07-12 — External-collections scans get an authoritative status surface (#271); the SPA timeout is retired](#2026-07-12--external-collections-scans-get-an-authoritative-status-surface-271-the-spa-timeout-is-retired)
- [2026-07-11 — Blazor Server UI removed (#91 phase b)](#2026-07-11--blazor-server-ui-removed-91-phase-b)
- [2026-07-12 — Live-E2E is a required step for API write-path handler changes (#303)](#2026-07-12--live-e2e-is-a-required-step-for-api-write-path-handler-changes-303)
- [2026-07-12 — TopBar primary-action button: wire creates, drop the rest (#238)](#2026-07-12--topbar-primary-action-button-wire-creates-drop-the-rest-238)
- [2026-07-13 — API versioning: the whole `/api` surface is mounted at `/api/v1`, additive-only after freeze (#286)](#2026-07-13--api-versioning-the-whole-api-surface-is-mounted-at-apiv1-additive-only-after-freeze-286)
- [2026-07-13 — Scheduling API hardening: null-name 500s, duplicate template items, unreachable 404 (#172)](#2026-07-13--scheduling-api-hardening-null-name-500s-duplicate-template-items-unreachable-404-172)
- [2026-07-16 — Functional-E2E CI harness: advisory curl-contract job over an app booted from source (#299)](#2026-07-16--functional-e2e-ci-harness-advisory-curl-contract-job-over-an-app-booted-from-source-299)
- [2026-07-16 — Optional advertised IPTV base URL (`iptv.base_url`) resolved centrally in the two generators (#340)](#2026-07-16--optional-advertised-iptv-base-url-iptvbase_url-resolved-centrally-in-the-two-generators-340)
- [2026-07-16 — Auto-tuning enumerates via EF, persists via SmartCollection; additive coexistence (#69)](#2026-07-16--auto-tuning-enumerates-via-ef-persists-via-smartcollection-additive-coexistence-69)
- [2026-07-16 — Per-playout reshuffle = scoped Reset build; seed surfaced (#71)](#2026-07-16--per-playout-reshuffle--scoped-reset-build-seed-surfaced-71)

---

## 2026-06 — REST API wraps existing MediatR handlers 1:1, no service layer

The REST API (#2, `docs/rest-api.md`) is thin controllers over the existing MediatR
Create/Update/Delete handlers — no new service/business-logic layer was introduced, since nearly
every handler already returns `Either<BaseError, T>`, which maps cleanly to HTTP status codes.
Latent handler bugs (missing existence checks, `KeyNotFoundException` risk, etc.) are fixed **at
the handler**, converting what would have 500'd into a proper 404/422 — not papered over in the
controller. Established across the #2a–#2e gap-issue PRs. Deep FK ids nested inside item-list
request bodies (e.g. a schedule item's `CollectionId`) are deliberately **not** existence-checked at
that depth, to avoid N+1 validation queries — precedent set by the schedules endpoints (#172); see
`docs/api-conventions.md` §3 for the up-to-date statement of this rule.

## 2026-06 — UI rebuild is a React SPA (ChicoryTV) on the REST API, not a Blazor reskin

#59 committed to a full SPA rebuild rather than reskinning Blazor Server pages. Blazor removal is
split into two phases under #91: **(a)** root-flip (SPA becomes `/`) + legacy-route redirects —
DONE, merged via PR #148 (`ErsatzTV/LegacyUiRedirects.cs`, `feat/91-cutover` → main). **(b)** full
Blazor removal — gated on every route having an SPA equivalent; tracked route-by-route in
`docs/blazor-route-parity.md`.

## 2026-07 — Response DTOs live in `ErsatzTV.Core/Api`, file-scoped `#nullable enable`

New REST response DTOs go in `ErsatzTV.Core/Api/<Domain>/*ResponseModel.cs` and mirror the shape of
the corresponding Application-layer ViewModel — controllers never expose VM types directly. Because
`ErsatzTV.Core.csproj` sets `<Nullable>disable</Nullable>` project-wide, any response-model file
with an optional member needs its own `#nullable enable` pragma at the top (most already have one).
`ErsatzTV.Application` has no nullable context at all — do not add `?` annotations to types living
there; that's a Core/Api-layer-only convention. Full detail: `docs/api-conventions.md` §2.

## 2026-07 — PUT-replace list endpoints derive `Index` from array order; alternate-schedules last row = catch-all default

For "replace the whole list" endpoints (PUT over a collection — schedule items, template items,
etc.), the item's `Index` is derived from its position in the request array, not from a
client-supplied index/order field — established by `ReplaceScheduleItemsRequest.ToCommand`
(`Items.Select((item, index) => item.ToReplaceCommand(index))`). Separately, `ProgramScheduleAlternate`
and `PlayoutTemplate` rows (both `IAlternateScheduleItem`) are evaluated in `Index` order,
first-match-wins; the convention is to place the least-conditional (or unconditional) row **last**
so it acts as the catch-all default. Established by the alternate-schedules work (PR #179,
`AlternateScheduleSelector.cs`).

## 2026-07 — Templates editor in the SPA is a table, not Blazor's drag-calendar

The legacy Blazor `TemplateEditor.razor` used a drag-and-drop day-grid calendar UI. The SPA
equivalent (`/app/templates/{id}`, PR #173) renders the same day/block assignment as a table
instead. This is an accepted, deliberate parity deviation — don't "fix" it to match Blazor's
interaction model without discussing it first.

## 2026-07-07 — API artwork contract: rooted URLs produced server-side

API response DTOs return artwork as rooted, directly-usable URLs (`/artwork/posters/...`,
`/artwork/thumbnails/...`, `/artwork/fanart/...`), plus passthrough for absolute `http(s)://` URLs
and Jellyfin/Emby proxy variants. Established by PR #181
(`ErsatzTV.Application/LibraryBrowse/Queries/GetLibraryBrowseItemsHandler.cs`, private `Artwork(...)`
helper — comment: *"Returns a rooted, directly-usable artwork URL for the SPA's `<img src>`... the
SPA [needs it pre-rooted]"*), then generalized into the reusable `ApiArtwork` helper
(`ErsatzTV.Core/Api/ApiArtwork.cs`, PR #183). Root cause: the SPA has no `<base href>`, unlike
Blazor, so relative artwork paths that worked for Blazor pages 404 in the SPA. Do **not** reuse the
Application-layer Mappers used by Blazor (e.g. `MediaCards`/`Television` mappers) for new API
DTOs — those still return old Blazor-convention relative paths; map from the domain/VM directly and
root the path via `ApiArtwork`.

## 2026-07-07 — Decode-style endpoints take a row id and look up server-side

Endpoints that decode/expand opaque stored state accept a database row id and resolve server-side,
rather than accepting client-supplied serialized state to decode. Established by
`GET /api/playouts/history/{id}` (`PlayoutController.GetHistoryDetails`, PR #182) — the row's raw
JSON (`Key`/`Details`) is decoded server-side into `PlayoutHistoryDetailsResponseModel`, the client
never round-trips the raw payload itself.

## 2026-07-07 — Season/episode/music-video drill-in via `parentId`, not new child-listing endpoints

Rather than adding dedicated child-listing endpoints per media kind (e.g. "list episodes of a
season"), the library-browse endpoint takes an optional `parentId` query param and the SPA drills
in by re-querying with it. Established across PRs #181/#183 (library-picker season drill-in, then
media-detail's season/episode/artist/music-video browsing). Avoids a combinatorial explosion of
per-kind child endpoints.

## 2026-07-07 — Convention docs read at session start, updated in-PR

`docs/api-conventions.md`, `docs/spa-conventions.md`, `docs/e2e-local.md`,
`docs/blazor-route-parity.md`, `docs/domain-model.md`, `docs/decisions.md`, and `docs/README.md`
are the standing reference set every ChicoryTV session should read before starting work, and each
one carries an explicit "update this doc in the same PR" rule rather than deferring doc updates to
a follow-up. These docs **replace per-session recon** — an agent reads the index
(`docs/README.md`) and the relevant convention doc instead of re-deriving conventions from the code
each time it starts API/SPA/E2E/parity work. A testing map and a generated-endpoint index are
tracked as still-to-come under #185. Drafting this doc set also surfaced a drift in
`ApiControllerSecurityTests.cs`'s hardcoded controller registry (several controllers under
`ErsatzTV/Controllers/Api/` are missing from it — see `docs/api-conventions.md` §6) — tracked as a
follow-up under #184 rather than fixed inline, since it's a pre-existing gap, not something this
doc-drafting pass caused.

## 2026-07-09 — Playback-troubleshooting completion feedback: poll status, no push channel

The SPA playback-troubleshooting screen (`PlaybackTroubleshootingScreen.tsx`, #145) reports FFmpeg
completion by **polling `GET /api/troubleshoot/playback/status` every ~2s** while a session is
running (plus one poll on mount so a session started elsewhere still gates Play), rather than a
server push. The status endpoint returns `{ state, exitCode, speed, logs }`; the screen captures the
running→completed/failed transition in local component state and surfaces a completion notice
(success on exit 0, warning otherwise) — the SPA equivalent of the Blazor page's MediatR
`ICourier`/`ISnackbar` `PlaybackTroubleshootingCompletedNotification`. Chosen over SignalR/SSE
because the SPA has **no push channel** and troubleshooting sessions are short and user-initiated, so
a lightweight poll (started on Play, stopped on settle/unmount) is simpler than standing up a new
real-time transport. Speed thresholds and the "(Speed: Nx)" badge colors are copied verbatim from the
Blazor `GetSpeedClass` (red <0.9, green >1.1, amber otherwise).

## 2026-07-09 — datetime-local instead of Chronic natural-language start parsing

The channel-mode "Date and Time" input in the SPA playback-troubleshooting screen uses a native
`<input type="datetime-local">`, a **deliberate deviation** from the Blazor page, which parsed a
free-text field with `Chronic.Core.Parser` (natural language like "yesterday at 8pm"). The SPA has no
Chronic dependency and a picker is unambiguous; the selected local datetime is sent to
`playback.m3u8` as an ISO-8601 `start` param via `new Date(value).toISOString()`, which the
controller binds to `DateTimeOffset?` exactly as the Blazor round-trip (`"o"`) format did.

## 2026-07-09 — SPA gates Download Media Sample while a session is active

Minor intentional deviation: the SPA playback-troubleshooting screen disables **Download Media
Sample** (alongside Download Results) while a troubleshooting session is starting/running; Blazor
only gated Download Results. Both downloads compete with the live transcode for I/O and the sample
archiver reads the same media file, so gating both during a session is strictly safer and costs
nothing (sessions are short).

## 2026-07-09 — OpenAPI spec mirrors the runtime Newtonsoft serializer (#198)

The generated OpenAPI document is made to follow the **runtime** JSON contract, not the reverse. Runtime
`/api/*` responses are serialized by Newtonsoft via `CustomContractResolver`/`CustomNamingStrategy`
(camelCase + a `FFmpegProfileId`→`ffmpegProfileId` special case + `[JsonProperty]` overrides such as
`ChannelResponseModel.FFmpegProfile`→`ffmpegProfile`), while `Microsoft.AspNetCore.OpenApi` generates the
spec from System.Text.Json metadata, whose camelCase drifted (`fFmpegProfileId`, `fFmpegProfile`). That
drift fed the SPA the wrong key. Rather than hand-patch the spec or change the wire format (breaking clients),
we added `NewtonsoftSchemaNamingTransformer` — an OpenAPI schema transformer registered on all three
documents that renames each schema property through the *same* Newtonsoft contract resolver the runtime uses,
so the spec matches the wire format by construction. A contract test
(`OpenApiSerializerContractTests`) serializes representative DTOs through the real runtime settings and pins
the spec property sets to them. Decision: **the wire format is the source of truth; the spec follows it via the
real contract resolver.** This also fixed a latent SPA bug (the channel-list "FFmpeg profile" column read
`fFmpegProfile` and always showed "Unassigned"). Issue #198.

## 2026-07-09 — YAML playout validator: paste-textarea instead of a server file path

The legacy Blazor YAML playout validator took a **server-side file path** (read directly off the
container's filesystem). The SPA's `YamlValidatorScreen.tsx` instead uses a paste `<textarea>` — a
deliberate deviation, not an oversight. The SPA runs entirely client-side against `/api/*` and has
no access to the server's filesystem, so a file-path field would either need a new
filesystem-browsing endpoint or silently fail; pasting the YAML directly is simpler and matches how
every other SPA editor already round-trips content through the API instead of the disk.

## 2026-07-09 — Channel numbers: prompt-driven sequential renumber instead of drag-to-reorder

The legacy Blazor channel list let you drag-and-drop rows to reorder channel numbers. The SPA
(`App.tsx`) instead offers a "Renumber" action that walks the list and asks for each channel's new
number via a sequence of native `prompt()` calls. Deliberate deviation: drag-to-reorder needs a
dedicated drag library and a bespoke reorder-persistence endpoint; a sequential prompt reuses the
existing per-channel update call and needs no new UI dependency. Revisit only if channel counts grow
large enough that prompt-per-channel becomes tedious.

## 2026-07-09 — "Table, not calendar" convention also covers the deco-templates editor

Extends the 2026-07 "Templates editor in the SPA is a table, not Blazor's drag-calendar" entry
above (not editing that entry — this generalizes it): the deco-templates editor
(`DecoTemplatesScreen.tsx`) follows the same convention, rendering its day/deco assignment as a
table rather than reproducing Blazor's drag-and-drop calendar grid. Same rationale, same
accepted-deviation status — don't "fix" either editor to match Blazor's interaction model without
discussing it first.

## 2026-07-11 — Trash "See all" reuses library-browse paging; search stays capped per kind (#213)

`GET /api/v1/search` still returns at most 100 items per media kind, which is the cheap first page for
the common case. For an overflowing kind, the SPA's "See all N …" action pages `GET
/api/v1/library/browse` with `query=state:FileNotFound`, `mediaType`, `pageNum`, and `pageSize=100`, then
appends the results client-side. This reuses the same `GetLibraryBrowseItems` query behind search,
adds no API surface, and only pays for follow-up requests when a kind exceeds the first-page cap.

## 2026-07-11 — Logs page-size is a client-local preference, not a server ConfigElement

The legacy Blazor Logs page persisted the user's chosen rows-per-page via
`ConfigElementKey.LogsPageSize` (`SaveConfigElementByKey`/`GetConfigElementByKey`), a
per-server-instance setting stored in the DB. `LogsScreen.tsx` instead persists it to
`window.localStorage` under `ctv-logs-page-size` (same wrapped-`Storage` pattern as
`designSystem.ts`'s theme preference: try/catch getter, validated against the known option set,
falls back to a default) and restores it on mount. Deliberate deviation: this is a per-browser UI
preference, not server/business state — no other client should see or be affected by it, so there
is no reason to round-trip it through the API and grow a new `/api/*` surface (or reuse the
generic config-element endpoints) just to store a page-size number. Follows the existing SPA
localStorage convention (`designSystem.ts` theme, `auth.ts` token) rather than introducing a new
persistence mechanism.

## 2026-07-11 — Logs column sorting: allow-listed `sortField`/`sortDirection` on `GET /api/logs`

Parity for `Logs.razor`'s `MudTableSortLabel` columns (Timestamp, Level — Message was never
sortable in Blazor either). `LogsController.GetLogs` adds `sortField` (`timestamp` | `level`,
default `timestamp`) and `sortDirection` (`asc` | `desc`, default `desc`) query params, normalized
server-side the same way `pageNum`/`pageSize` are clamped rather than rejected with a 422: an
unrecognized `sortField` silently falls back to `timestamp`, an unrecognized `sortDirection` falls
back to `desc` — the pre-existing default behavior (newest-first) is unreachable to break via a bad
query string. `LogsScreen.tsx` renders the two sortable headers as buttons with a chevron
indicating the active field/direction; clicking the active column toggles direction, clicking the
other column switches to it ascending.

## 2026-07-09 — Per-playout "Schedule reset" button dropped; Reset uses the server-default build mode

Blazor's playouts page had both a per-playout **Reset** and a separate **Schedule Reset** control
(setting the daily rebuild time). The SPA keeps Reset — `POST
/api/channels/{channelNumber}/playout/reset` with no `mode` param, so the server picks the same
default Blazor used (Classic → Refresh, everything else → Reset) — but drops the dedicated
"Schedule reset" button: the daily rebuild time is already editable through the playout's
Edit-details flow, so a second entry point would duplicate an existing capability. Deliberate
deviation, not a lost capability. Issue #210.

## 2026-07-09 — Collection custom order: move up/down buttons, any-kind collections

Blazor reordered collection items with SortableJS drag-and-drop and only enabled custom ordering
for movies-only collections. The SPA (`CollectionsScreen.tsx`) uses per-row **Move up / Move
down** buttons in an explicit reorder mode instead of drag (no new drag dependency; the mode loads
ALL items first because `PUT /api/collections/{id}/custom-order` replaces the whole order from
array position — submitting a partial page would scramble the rest), and does **not** replicate
the movies-only gate: the API and the playback-side `CustomOrderCollectionEnumerator` sort by
`CustomIndex` regardless of item kind, so the SPA offers reorder for any manual collection with
custom order enabled. Issue #211.

## 2026-07-10 — Shared "Add to…" layer lives in `web/src/media/addTo/`; select-mode is an explicit toggle

The media mutation surface (#208/#209) is built on one reusable component group,
`web/src/media/addTo/` (media-domain components, like `MediaPosterCard` — not generic
`components/`): `AddToCollectionDialog` (existing-collection Select + inline "(New collection)"
create, Blazor `AddToCollectionDialog.razor` parity), `AddToPlaylistDialog` (group → playlist
Selects, no inline create), `AddToScheduleDialog` (schedule Select; payload replicates Blazor's
`AddProgramScheduleItem.ForMediaItem` defaults — see `addTo/scheduleItem.ts`),
`SaveAsSmartCollectionDialog`, and `AddToMenu` (the drop-in popover for cards/detail pages via
`MediaPosterCard`'s `actions` slot). New screens wanting add-to affordances use this layer —
don't build screen-local pickers. Two deliberate deviations from Blazor, applied consistently on
the search and browse screens: **(1) multi-select is an explicit screen-level "Select" toggle**
(off = cards open, on = cards select) rather than Blazor's always-on corner-select, because
`MediaPosterCard`'s select handler takes over the card's single click gesture; **(2) the
per-card menu offers collection/playlist for a single item of any kind, plus schedule only for
shows/seasons/artists** — collection/playlist is a superset of Blazor's per-card collection-only
menu, while the schedule target is gated to exactly the kinds Blazor's
`AddProgramScheduleItem.ForMediaItem` call sites offer, because the server validator
(`ProgramScheduleItemCommandBase.CollectionTypeMustBeValid`) accepts only the
TelevisionShow/TelevisionSeason/Artist per-media-item CollectionTypes and 422s the rest.
"Add All" (query-wide) mirrors Blazor's two-step: materialize ids
via `GET /api/search/all-items`, then reuse the id-list add endpoints — no query-based add
command exists server-side. Issues #208/#209.

## 2026-07-10 — Schedule-item GET returns a flat, non-polymorphic DTO (`ScheduleItemResponseModel`)

`GET/POST/PUT /api/schedules/{id}/items` return `ScheduleItemResponseModel` /
`ScheduleItemsResponseModel` (`ErsatzTV.Core/Api/Scheduling/`), **not** the Application-layer
`ProgramScheduleItemViewModel` hierarchy (One/Flood/Multiple/Duration subtypes). The polymorphic VM
only described its base shape in OpenAPI, so the SPA couldn't see the subtype fields (issue #126).
The flat DTO promotes every subtype field to a nullable top-level member — `multipleMode`,
`multipleCount` (renamed from the VM's `Count`), `playoutDuration`, `tailMode`,
`discardToFillAttempts` — mapped by pattern-matching the concrete VM in
`ScheduleItemResponseMapper` (`ErsatzTV.Application/ProgramSchedules/`). Its **mutation fields are
named 1:1 with `ScheduleItemRequest`** so a GET maps losslessly back to a PUT/POST
(`ScheduleItemResponseRoundTripTests` is the release gate proving the fixed point). It also carries
picker-hydration fields the editor needs: `collectionName`/`smartCollectionName`/…/`playlistName`,
`playlistGroupId` (to preselect the playlist's group), per-filler names, `watermarks` /
`graphicsElements` as `NamedIdResponseModel` lists, the computed `name`, and `durationEstimate`.
`GetProgramScheduleItemsHandler.EnforceProperties` still rewrites StartType→Dynamic, Flood→One and
Playlist/Rerun→PlaybackOrder None when `ShuffleScheduleItems` is on — that lossy normalization is
deliberate and lives on the read side (documented + tested). New shared `NamedIdResponseModel`
(`ErsatzTV.Core/Api/`) is the generic `{id, name}` embed for API responses. Issues #126/#207/#212.

## 2026-07-10 — Playout API mutations return 409 while the build lock is held (#215)

Blazor disabled per-playout Reset/Erase/Delete/Edit while a `BuildPlayout` was in flight
(`EntityLocker.IsPlayoutLocked`, `Playouts.razor` + per-kind editors); the REST API had no
equivalent, so a client could race an in-flight build with a destructive `ExecuteDelete` and leave
a half-built playout. Adversarial-reviewer#18 promoted this to a #91-phase-(b) removal gate: after
Blazor is deleted the invariant would vanish entirely.

Decision: enforce the invariant **server-side** on the API rather than re-implementing a live push
channel. `PlayoutController` and `ChannelController` inject `IEntityLocker`; every id-keyed mutation
— `PUT /api/playouts/{id}`, `.../deco`, `.../alternate-schedules`, `.../templates`,
`POST .../erase-items`, `.../erase-items-and-history`, `DELETE /api/playouts/{id}`, and
`POST /api/channels/{channelNumber}/playout/reset` — checks `IsPlayoutLocked(id)` first and returns
**409 Conflict** (`ApiResults.ConflictProblem`, new shared helper mirroring `NotFoundProblem`) while
the build lock is held. The PUTs are gated too (not just the destructive ops): the target invariant
is "no mutation during a build", matching Blazor's edit-disable.

- **The guard is advisory check-then-act, not mutual exclusion** — same posture as Blazor's disabled
  buttons. A `BuildPlayout` already sitting in the worker queue can take the lock a few milliseconds
  after the check passes, so the original race is *narrowed*, not eliminated; consequences remain
  self-healing (the next rebuild corrects a half-mutated playout). True prevention — having each
  mutation acquire the playout lock for its duration — was deliberately not taken: `LockPlayout`
  publishes `PlayoutUpdatedNotification` (UI churn per mutation) and would make mutations block
  builds, a semantics change out of scope for restoring Blazor parity.

- **`reset-all` is deliberately NOT gated** — it stays 202. `ResetAllPlayoutsHandler` already
  *silently skips* locked playouts, which matches Blazor and the handler semantics; a fire-and-forget
  bulk enqueue always accepts.
- **SPA mirrors the lock via data, not a push channel** — `PlayoutListItemResponseModel` gains an
  `IsLocked` bool (set from `IsPlayoutLocked` in the controller's list projection). The playouts
  screen disables Reset/Erase/Erase-and-history/Delete for a locked row and shows a "Building…"
  Badge; on a 409 from any mutation it surfaces the error and calls `query.refresh()` so the row
  picks up the flag. No new polling was added (the existing 30s channel-state poll is unchanged).

Precedent for the 409 shape: `TraktController` (left as-is with its own private `ConflictProblem()`
to keep the diff small). Convention recorded in `api-conventions.md` §3a.

## 2026-07-11 — Schedules SPA editor: draft/explicit-Save over instant-persist; Copy includes multi/smart/rerun; shuffled-GET normalization preserved

The ChicoryTV schedules editor (`web/src/screens/SchedulesScreen.tsx` + `web/src/schedules/`,
issue #207) rebuilds the schedule-item lineup to full mutation parity with the legacy Blazor editor.
Three deliberate decisions:

**(a) Draft model with one explicit Save, replacing instant-persist.** All add/edit/copy/remove/
reorder mutate a **local draft list only**; a single **Save** issues one
`PUT /api/schedules/{id}/items` (the replace endpoint). This is intentional because that PUT is
**destructive server-side** — it deletes and recreates every item row (new ids) and triggers playout
rebuilds — so batching edits into one flush (vs. the old per-action POST/DELETE/PUT) minimizes churn
and gives the user a Discard/dirty affordance. On 422/network error the draft is kept and the error
surfaced; on success the draft is replaced with the server response. A **Discard** action and a dirty
guard (native `confirm()` on schedule-switch + in-app nav via `navigationGuard.ts`, plus a
`beforeunload` listener) protect the draft. See `docs/spa-conventions.md` §8. This retires the old
inline `ScheduleScreen` in `App.tsx` and its instant-persist add/delete/reorder tests.

**(b) Copy item deep-copies ALL source references, including multi/smart/rerun collections.** Blazor's
`CopyItem` omitted the multi-collection / smart-collection / rerun-collection references when
duplicating an item (copying only the plain collection/media-item/playlist refs) — a latent bug. The
SPA's `copyDraftItem` (`web/src/schedules/itemRules.ts`) copies every source field + display name, so
copying a MultiCollection/SmartCollection/Rerun item preserves its source. Deliberate deviation
fixing the Blazor omission.

**(c) The shuffled-schedule GET normalization (`EnforceProperties`) is preserved lossiness, matching
Blazor.** When a schedule has `ShuffleScheduleItems`, `GET .../items` still rewrites startType→Dynamic,
Flood→One, and Playlist/Rerun playbackOrder→None (and zeroes discardToFillAttempts for non-random
Duration items). The SPA does **not** fight this — it hides the Fixed start type and Flood playout
mode from the option lists (and disables the reorder arrows) for shuffled schedules, mirroring Blazor,
so a GET→edit→PUT round-trip stays consistent with the server's read-side normalization. Issue #207.

## 2026-07-11 — Channel editor: bare-create entry point + external-logo mutual exclusion (#212)

Two Blazor-parity decisions closing the channel-editor gaps (`ChannelEditor.razor` +
`ChannelEditViewModel`):

1. **Bare-channel create lives on the channels list, not a form-first route.** Blazor's
   `/channels` (no `Id`) is a full add form; the SPA instead adds a "New blank channel" action next
   to "Add Channel" on `ChannelsScreen` (`web/src/App.tsx`) that POSTs `CreateChannelRequest` with
   Blazor's computed add-mode defaults (`(max existing int-parsed channel number) + 1`, `name: "New
   Channel"`, `group: "ErsatzTV"`, `ffmpegProfileId` = `GET /api/settings/ffmpeg`'s
   `defaultFFmpegProfileId`, `streamingMode: "TransportStreamHybrid"`, `isEnabled`/`showInEpg: true`,
   every other field at its C# `default(T)` — see `ChannelEditor.razor`'s `else` branch for the
   source of truth) directly, then navigates to `/app/edit-channel/{id}` for the rest of the fields.
   This is a deliberate equivalent, not a parity gap: it reuses the existing full editor instead of
   duplicating its ~20 fields into a second form. "Add Channel" (`/app/new-channel`, the
   library-to-lineup `ChannelBuilder` flow) is unrelated and untouched.
2. **External logo URL wins over an uploaded logo, mirroring
   `ChannelEditViewModel.ToUpdate/ToCreate`.** The channel's logo is `ArtworkContentTypeModel {
   path, contentType, isExternalUrl }`; on hydration, `isExternalUrl: true` populates a separate
   "External logo URL" field and the uploaded-logo draft state is treated as empty (`EMPTY_LOGO =
   { path: '', contentType: '' }` in `ChannelEditScreen.tsx`) so the two never disagree. On submit,
   a non-blank URL always wins: `logo: { path: url, contentType: '' }`, exactly matching
   `ExternalLogoUrl`'s precedence in the C# view model. Uploading a file clears the URL field (the
   last-set field wins, Blazor parity via `UploadLogo`'s `_model.ExternalLogoUrl = null`). The URL
   is validated as http(s) client-side before save is enabled (Blazor has no equivalent validation;
   added because the field is free text with no server-side format check surfaced to the SPA).

Also landed with #212: `preferredAudioLanguageCode`/`preferredSubtitleLanguageCode`,
`musicVideoCreditsTemplate`, and `streamSelector` moved from free-text `Input`s to `Select`s fed by
`GET /api/languages` / `/api/channels/music-video-credits-templates` /
`/api/channels/stream-selectors`. Each keeps the channel's currently-stored value selectable even if
it's absent from the reference list (`optionsKeepingCurrent` in `ChannelEditScreen.tsx`) so loading
an existing channel never silently changes the value out from under an unmanaged language code or a
template/selector file removed from disk since save.

## 2026-07-11 — Queue state lives in the pinned Gitea tracker (#237), not in the handoff file

With multiple sessions/agents working the repo in parallel, the old protocol — every session
wholesale-rewrites `docs/handoffs/chicorytv-issue-queue.md` on main (session state + queue +
next-session prompt) — became a last-writer-wins race. New protocol: **volatile queue state
moved to Gitea**, which is concurrency-safe by construction. Pinned tracker issue **#237**
holds the goal + ordered arc in its body (edited rarely, only on arc changes, re-read before
edit) and an append-only session-comment log (fixed template: Closed / Filed / Triage /
Arc change / Recommended next). Milestone `Blazor removal (#91 phase b)` + the `review` and
`in-progress` labels are the machine-queryable view. Sessions **claim** an issue before working
it (`in-progress` label + claim comment; the tiny read→claim race window is accepted, later
claimant backs off; stale claims — no commits/comments ~48h — may be taken over with a comment).
Every new issue gets an explicit end-of-session triage verdict — gate-blocker (milestone + arc
slot) or backlog (label only) — so review findings adjust the queue only through that step and
the arc doesn't drift. The handoff file keeps only the **static kickoff prompt** and the
**append-only Lessons lore** (per-session prompts are gone; task context lives in issue bodies).

## 2026-07-11 — EntityLocker: atomic flags + single-owner release discipline, no owner tokens (#231)

`EntityLocker` (process-wide singleton, `ErsatzTV.Infrastructure/Locking/EntityLocker.cs`) is the
advisory "operation on entity X is in progress" mutex layer. Adversarial review (#20/F5, →#231)
found three defects: six plain-`bool` flags with a non-atomic check-then-set (two threads could both
acquire and both return `true`), tokenless `Unlock*` letting any caller release another owner's lock
(e.g. `BuildPlayoutHandler` ignored `LockPlayout`'s return then unconditionally unlocked in
`finally`), and one batch taking a single `LockLibrary` released after the *first* of two enqueued
scan units (so the second ran unlocked).

**Model chosen: tokenless atomic flag + documented single-owner release discipline.** The six bools
became `int`s guarded by `Interlocked.CompareExchange` (0/1), so `Lock*`'s `bool` return is now a
reliable "this call won the transition" signal and the change event fires exactly once per
transition. The contract (XML-doc'd on `IEntityLocker`): a `true` from `Lock*` confers ownership of
exactly one release — performed either in the acquiring scope (`finally`, gated on the captured
bool) or by the single designated releaser the acquirer hands off to (the consumer of the message
enqueued while holding the lock, with a compensating unlock if the enqueue throws — the established
`TraktController.EnqueueWithTraktLock` / scheduler `unlock: last` tail pattern). Callers must never
release a lock they did not acquire. `Unlock*` on an already-unlocked slot returns `false`, fires no
event, and logs a Warning — the loud tripwire for double-release bugs; it does not throw or
`Debug.Assert`, because an advisory flag must stay safe to release in `finally` paths. The three
`ConcurrentDictionary`-backed kinds (Library/Playout/RemoteMediaSource) were already atomic
(`TryAdd`/`TryRemove`) and kept their semantics (the redundant `ContainsKey` pre-checks were dropped
as tidy-up); the interface signature is unchanged across its ~40 call sites.

**Rejected:** owner tokens/leases — the acquirer and releaser for Library/Trakt/Plex/Collections
locks are different code correlated only by entity id across in-memory `Channel<T>` queues, so a
token would have to travel inside ~8 background-request message types for a defect that discipline
plus the now-trustworthy atomic return value already prevents. Counted/reentrant locks — wrong
semantics: these are exclusive in-progress flags; two holders is the failure mode, not a feature.
Call-site fixes this model prescribes land separately: #232 (scan lifecycle — enqueue only after a
successful lock, compensating unlock on enqueue failure, one release per acquisition in batches) and
#234 (BuildPlayout/subtitles gate their `finally` unlock on the captured acquire result).

## 2026-07-11 — Media-source management REST write API + SPA (#202)

Replaced the Blazor `/media/sources/{local,plex,jellyfin,emby}/...` pages (14 routes) with SPA
screens under `/app/libraries/*` over new write controllers (`LocalLibrariesController`,
`Plex|Jellyfin|EmbyMediaSourcesController`), wrapping existing MediatR commands 1:1 (no new
commands, no DB migration). Full design + adversarial-review reconciliation:
`docs/handoffs/` session record and issue #202. The design surfaced and fixed several pre-existing
Application/Infrastructure bugs newly reachable from a programmatic client; each is recorded here
because it changes documented behavior, not just adds a route.

**Secure `apiKey` contract (Jellyfin/Emby connection).** The connection GET
(`RemoteConnectionResponseModel`) returns `{ address, hasApiKey }` — the stored key **never**
leaves the server, closing a leak where the old design would have served the raw key from an
unauthenticated GET under any-origin CORS. On the connection PUT, a blank/omitted `apiKey` means
*retain the existing key*; a non-blank value sets a new one; the key is **required on first
connect** (no existing secret) → 422. Rationale: GETs aren't behind `X-Api-Key`
(`ApiKeyAuthorizationFilter` only guards mutating verbs), so a secret-bearing GET is a real
exposure regardless of how obscure the route is. **Stated explicitly as an input to #197** (the
planned read-side-auth review for secret-bearing GETs) — #197 should treat "does any GET return a
credential" as one of its checks, not just this one instance.

**Three list-replace identity contracts, not one uniform one.** An earlier draft assumed a single
"`Id<1`=add / missing=delete / id-preserved" contract across all three PUT-replace families; source
inspection proved that false for two of them:
- *Remote library sync preferences* (`PUT .../{id}/libraries`) — the command carries no source id
  and the handler toggles only the ids present in the body; a row **absent** from the request is
  left untouched, not deleted (libraries are sync-discovered, never created via this PUT, so there
  are no `Id=0` adds either). The controller validates the submitted id set against
  `Get{Family}LibrariesBySourceId(id)` (422 on any id not owned by the route's source — closes a
  cross-source hole). Identity is **not stable across a disable**: `Disable{Family}LibrarySync`
  removes and re-adds the row with a fresh id, so the SPA keys its draft to `(name, mediaKind)`,
  never to `Id`, and refetches after every save (the PUT returns the reloaded list).
- *Path replacements* (`PUT .../{id}/path-replacements`) — id-based (existing `Id`=update,
  `Id<1`=add, absent=delete) as documented, **but** the repo UPDATE SQL had no source-id predicate
  (`WHERE Id = @id`, no `AND {Family}MediaSourceId = @id`), so a PUT to source A could silently
  overwrite source B's row with the same numeric id. Fixed with a handler-level ownership guard
  (reject any incoming positive id not in this source's current set → 422, no partial mutation)
  **and** the repo SQL predicate itself (defense-in-depth for any other caller of that repo method).
- *Local library paths* (`PUT /api/libraries/local/{id}`) — identity is the **normalized path
  string** (full path, trailing-separator/case-insensitive), not `Id`; `Id` in the request is
  advisory. Renaming a path is delete-old+add-new under the hood (its `LibraryPath.Id` changes).
  Kept as-is (matches the entrenched, tested Blazor behavior and how the SPA edits by value); not
  rewritten to id-based identity, which would be a bigger, riskier change out of #202's scope.

**Plex pin-flow as REST: poll until the lock releases, exception-safe non-handoff unlock.** The
SPA polls `GET /api/media-sources/plex` rather than a per-pin status resource (no pin-addressable
server state exists to expose; SSE/push was already rejected, 2026-07-09). Polling contract is
`isLocked && !isAuthorized` = waiting on the user; `isLocked && isAuthorized` = finalizing
(discovering servers — **do not** stop here, the server list is still empty);
`!isLocked && isAuthorized` = success; `!isLocked && !isAuthorized` = timed out/abandoned. This
required fixing a **latent lock-leak bug**: `TryCompletePlexPinFlowHandler` threw
`OperationCanceledException` on its 2-minute timeout instead of returning `false`, and nothing
unlocked on that path — an abandoned sign-in wedged the Plex lock until restart or manual sign-out.
Fix releases `UnlockPlex()` on the timeout-throw, a poll-exception, and an enqueue-exception — but
**deliberately not** in an unconditional `finally`: on success the lock is handed off to
`SynchronizePlexMediaSources`, the sole releaser after server discovery; a blanket `finally` would
double-release and release *before* discovery completes, re-opening the same race the fix closes.
This is the same non-owner-token discipline as the #231 `EntityLocker` model (2026-07-11 entry
above), applied to the pin-flow's handoff-vs-terminal distinction specifically.

**404 comes from the controller pre-check, not the handler.** `Apply`/`ToEitherAsync` both
`.Join()` errors, which flattens any `NotFoundError` inside a joined `Validation` down to a plain
422. So every id-taking endpoint's real 404 is a controller-side pre-check
(`Get...ById(id)`-is-`None` → `ApiResults.NotFoundProblem`, the `TemplateController.DeleteGroup`
pattern), not a handler-level conversion — converting the joined validators to `NotFoundError`
would be dead code, since the join discards the distinction anyway. This is check-then-act (a
delete racing between the pre-check and the command falls through to the handler's own 422, not a
404); accepted and tested against the actual runtime error type rather than a hoped-for handler 404.

**"Scan All" dropped, not implemented.** The disabled SPA header button on the libraries hub was
speculative UI with **no Blazor equivalent** (`Libraries.razor` only ever supported per-library
scan). Removed rather than backed with a new bulk-scan endpoint; per-library scan (#232) and the
new per-source refresh-libraries endpoints (P8/J9/E9) cover the real capability set.

**App-owned popstate for guarded sub-path routes.** `LocalLibraryEditScreen` and the other
`/app/libraries/*` editors are the first screens to both register a dirty-navigation guard *and*
track their own sub-path pathname — the combination `spa-conventions.md` §8 had flagged as
unvalidated. React commits child passive effects before parent ones, so a sub-path wrapper that
self-registers `popstate` would fire (and switch sub-screen) *before* App's guard-restore listener
could veto. Resolution: App owns `popstate` centrally for the `libraries` route and only pushes an
approved sub-path down to the wrapper (which no longer self-registers `popstate`); on a vetoed pop
App re-pushes the pre-pop URL and the wrapper never sees the rejected path. This is scoped to the
`libraries` route only (gated on `activeRoute === 'libraries'`) so unguarded sub-path routes
(Playouts, Media) stay byte-identical. See `spa-conventions.md` §2/§8 for the updated exemplar
list and the resolved caveat text.

## 2026-07-11 — Legacy→SPA redirect matcher: exact map + ordered segment-template patterns (#204)

`LegacyUiRedirects.TryGetRedirect` grew from a single exact-path dictionary to a **two-tier matcher**
behind the unchanged `(PathString, out string)` signature. **Tier 1** is the existing
`OrdinalIgnoreCase` `Map` (now 52 entries — the parameterless (A)/(B) routes plus the (E-base) browse
roots whose *targets* carry `?kind=…`). **Tier 2** is an ordered `IReadOnlyList<PatternRule>` of 36
segment-template rules ((C)/(C2)/(D)/(E-page)), consulted only on a Tier-1 miss; declaration order is
match order (first-match-wins).

Template tokens are minimal: `{id}` matches a **strict positive integer**
(`int.TryParse(seg, NumberStyles.None, InvariantCulture, out id) && id > 0` — rejects signs,
whitespace, separators, `0`, negatives, and overflow like `999999999999`; the raw segment text,
e.g. `007`, is substituted, not re-formatted); `{any}` matches any non-empty segment and is dropped
(only `/playouts/add/{any}`); everything else is a literal compared `OrdinalIgnoreCase`. The request
path is split with `StringSplitOptions.None` and **empty segments are rejected** (load-bearing: so
`/channels//5` cannot match `/channels/{id}`); templates themselves use `RemoveEmptyEntries`. The
existing single-trailing-slash normalization runs before both tiers, so `/channels/5/` matches.

The set is **collision-free by construction** — exact-before-pattern plus strict numeric `{id}` means
no two tiers/rules can match the same path. **Guard invariant** (comment + `Map`-keys meta-test): no
Tier-1 key or Tier-2 template may begin with `/api`, `/artwork`, `/docs`, `/openapi`, `/iptv`, `/app`,
or `/media/sources`; rules are always full, specific templates — **never prefix wildcards** (a bare
`/media/{any}` rule is forbidden). The blazor branch does not prefix-guard `/api|/artwork|/docs|
/openapi`, so the matcher's specificity is part of their protection.

**Query-string merge**: the incoming request query is now merged into the target via a new public
`AppendQueryString(target, QueryString)` helper (one-line Startup change:
`context.Request.PathBase + LegacyUiRedirects.AppendQueryString(target, context.Request.QueryString)`).
A target that already carries `?` (the `?kind=…` browse roots) is `&`-joined instead of producing a
malformed double `?`; plain targets keep verbatim-append behavior byte-for-byte. A duplicated key
after a merge (`?kind=movies` + incoming `?kind=shows`) is first-wins in the SPA
(`URLSearchParams.get` returns the first value) — acceptable. Extracting the merge into
`LegacyUiRedirects` keeps it unit-testable without a TestServer while preserving the PathBase
re-application invariant the Startup source-text test protects.

**Rejected**: regex pairs (harder to audit for the `/api`/`/artwork` greediness invariant, noisier
tests, no benefit — every parameterized route here is "fixed segments + one variable segment");
ASP.NET `TemplateMatcher`/`RouteMatcher` (pulls routing machinery into a static helper for 36 rules);
a single unified rule list (loses the O(1) dictionary hit for the ~52 exact routes that dominate real
traffic). No `/api` change, no OpenAPI regen, no SPA change.

## 2026-07-11 — Pre-removal Blazor rollback tag `blazor-final` (#205)

Removal-gate item #205: the removal PR deletes both the Blazor reference implementation and the
`/system/health` escape hatch, so a post-deletion parity gap would otherwise be an archaeology exercise
(guessing which release tag still matches `main` minus Blazor). Decision + procedure, to run as the **first
action of the Step 2 deletion PR merge** (not before — `main` moves until then):

1. On the `main` commit **immediately preceding** the removal merge (the last commit that still contains
   `ErsatzTV/Pages/**`), cut an annotated tag and push it:
   `git tag -a blazor-final -m "Last commit with the legacy Blazor Server UI (pre-#91-phase-b removal)"`
   then `git push origin blazor-final`. The tag name is **`blazor-final`** (not `v*`) so it does **not**
   trigger the `v*` prod-release build in `.gitea/workflows/docker-build.yml`.
2. **Restore path** (if a gap surfaces post-removal): `git checkout blazor-final` → `docker build -f
   docker/Dockerfile -t ersatztv:blazor-final .` → pin the **test** container to that image while the gap is
   fixed forward on `main`. Alternatively `git revert` the single deletion merge commit (keep the deletion as
   one squash/merge commit specifically to make this a one-liner).
3. Document the tag + restore path in the removal PR body; update this entry with the tag's commit sha when
   cut.

Not cut this session — `main` still carries Blazor and will advance before the removal PR.

## 2026-07-11 — Async-op API contract normalization + playout build observability + F9 scan endpoints (#235)

Reviewer#20 F7/F8/F9. Normalizes the queue-triggering `/api/*` endpoints onto one contract, closes the two
F9 `Libraries.razor` parity gaps, and hardens the Trakt batch-lock lifecycle. Much of the F8 surface was
**already normalized** by #232 (library scan → `QueueLibraryScanResult` 202/404/409/422) and #215 (per-id
playout mutations + reset → 409 lock guard) — this issue finished the remaining outliers.

**Normalized async-op contract** (queue-triggering endpoints): **202 Accepted** = work queued; **404
ProblemDetails** = entity missing (controller pre-check); **409 ProblemDetails** = lock held (the running
job, or a mutation racing it — §3a/§3b); **422 ProblemDetails** = domain precondition (sync disabled /
unsupported / start failed). Trakt was the reference implementation. Changes made:
- `MaintenanceController.EmptyTrash` — error path **500 text/plain → 404/422 ProblemDetails** (`ToErrorResult`).
- `MaintenanceController.CleanArtwork` — silent **200 → 202** (fire-and-forget enqueue). No SPA consumer.
- `LibrariesController.ScanShow` — conflated **400 `{error}` → 202/404/409/422** via a new
  `QueueShowScanResult` enum (6 outcomes incl. an honest `ScanFailed`→422, distinct from `Unsupported`).
- `ChannelController.ResetPlayout` — **200 → 202** (queue-triggering; 404/409 unchanged).
- `PlayoutController.ResetAll` — **202 (no body) → 202 + `ResetAllPlayoutsResponseModel`** reporting
  `queuedPlayoutIds` / `skippedLocked` / `skippedUnsupported` (replaces the silent skip; still 202, still
  skips locked/ExternalJson by design per §3a — now it *reports* what it skipped).
- `TroubleshootController.TroubleshootPlayback` — bare body-less `NotFound()` → **404/422 ProblemDetails**
  with distinguishing detail. **Status codes the SPA HLS player depends on were preserved** — verified
  `HlsPlayer.tsx` never branches on this endpoint's status (playback state comes from the separate
  `/api/troubleshoot/playback/status` poll); only the error *body* was enriched.

**Playout build observability**: the list endpoint (`GET /api/playouts`) already stamped `isLocked` +
`BuildStatus` on `PlayoutListItemResponseModel` (#215); this issue adds **`isLocked` to the single-playout
`GET /api/playouts/{id}`** (`PlayoutResponseModel`), so the detail poll surface carries the §3a lock flag
too. No dedicated `GET /api/playouts/{id}/status` push channel was added — the flag on the existing GETs is
the HTTP-observable substitute for Blazor's live lock event, matching the `GET /api/trakt/status` precedent.

**F9 parity endpoints** (the `Libraries.razor` deletion gate — #202 did NOT close these):
- **Deep scan**: `POST /api/libraries/{id}/scan` gains `?deep=false`, threaded through
  `QueueLibraryScanByLibraryId(LibraryId, DeepScan=false)` into `ForceSynchronize{Plex,Jellyfin,Emby}LibraryById(id, deep)`
  (was hardcoded `false`). Non-breaking: existing callers omit it.
- **External-collections scan**: new `POST /api/media-sources/{plex|jellyfin|emby}/{id}/scan-collections?deep=false`
  on the three #202 media-source controllers, dispatching `Synchronize{X}Collections(id, ForceScan:true, deep)`.
  Each pre-checks source existence (404), acquires the per-source **collections** lock (`Lock{X}Collections()` —
  the lock *is* the running scan, so a false = **409**), then enqueues and returns 202; the controller
  compensating-unlocks in a `catch` if the enqueue throws (§3b), and `ScannerService` releases in its `finally`.
  Thin SPA clients shipped (`scanLibrary(id, deep)`, `scanCollections`); **the SPA deep-scan / collections
  buttons are the removal PR's remaining parity work** (parity doc §5).

**F7 Trakt batch-lock leak fix**: the global Trakt lock was released only when the *terminal* batch message
(`Unlock: true`) was processed; a `WorkerService` shutdown/cancellation before that message leaked the lock
permanently (subsequent Trakt ops 409 until restart — same class as #231/#233/#234). Fix: `WorkerService`
now releases the Trakt lock in a `finally` on read-loop exit if still held. Non-vacuous regression test proven
against an inverted-condition control.

**Accepted-by-design** (per the issue's decision-record ask): the worker's channels are **unbounded** and
there is **no shutdown drain** — messages still queued at process exit are dropped. This is acceptable because
the entity locks are **in-memory singletons that die with the process**, so a dropped message can't strand a
lock across restarts (the F7 `finally` covers the *within-process* shutdown-break leak, which is the only way
a lock outlives its batch while the process keeps running). Adding a bounded-channel backpressure / graceful
drain is out of scope and would not fix a correctness bug.

## 2026-07-11 — Post-commit side effects run on `CancellationToken.None` (generalized from #251 to #254)

Audit #22 (adversarial-reviewer) found ~20 command handlers threading the request `cancellationToken`
into work that runs **after** `SaveChangesAsync` commits — the post-commit `WriteAsync` enqueue that
rebuilds/refreshes the affected entity, `mediator.Publish`, search-index reindex, cache refresh. A late
HTTP-client disconnect cancels that token, so the *already-committed* mutation throws on the way out
**and silently drops its side effect** (the playout rebuild is never queued → the persisted edit never
takes visible effect until a manual Reset). #251 fixed this for the deco handlers; #254 generalizes the
policy across the codebase.

**Decision.** Once a mutation has committed, the *entire* compensating side effect — enqueues, publishes,
reindexes, cache refreshes, and any post-commit lookup that **gates** one of those enqueues — runs on
`CancellationToken.None`. The commit is the point of no return; past it the side effect must not be
half-abortable. Full convention + the two boundaries in `docs/api-conventions.md` §7b.

**Scope of the #254 sweep (this PR).** Swept the single-`SaveChanges` handlers under `MediaCollections/`,
`ProgramSchedules/`, `Playouts/`, `Channels/` (20 handlers). Deliberately **excluded**:
- **`BuildPlayoutHandler`** — a background/worker handler; its token is the worker shutdown token, not a
  client-disconnect token, so its downstream enqueues *correctly* honor cancellation.
- **`UpdateFFmpegSettingsHandler` + the two `Configuration/` settings handlers** — they commit via several
  sequential `IConfigElementRepository.Upsert` calls with an interleaved enqueue; "when is it committed"
  is a partial-commit-under-cancellation question broader than the clean single-`SaveChanges` F4 pattern.
  Left for a separate follow-up.
- **Response-projection reloads** (`ReplaceProgramScheduleItemsHandler` / `AddProgramScheduleItemHandler`
  post-commit graph reload that builds the *returned* view model) keep the request token — a cancelled
  response after a durable commit + `None`-enqueue loses nothing.
- Handlers a no-token `WriteAsync()` already makes behaviorally correct (`default` == `None`) were left
  alone (explicit-`None` there is cosmetic).

Also folded in the two other #254 items on the same handlers: the channel-guide `{number}.xml` delete in
`DeleteChannelHandler`/`DeletePlayoutHandler` now routes through `IFileSystem.File.Delete` (observable
under `MockFileSystem`) **before** the commit (a post-commit delete orphans the xml on a crash; the guide
xml is regenerable on demand, so a pre-commit delete is the safe ordering), and
`ReplacePlayoutAlternateScheduleItemsHandler` now rejects an empty item list in the handler (not only at
the controller pre-guard) so a direct caller can't trip the `Max()`-on-empty crash.

**Coordination note for #253 PR2–PR4.** Those PRs add `Version++` (pre-commit) to the mutating handlers of
the versioned aggregates — several of which this sweep also touched (post-commit token, a different line
region). Low git-conflict risk, but merge `main` in and expect to see the `CancellationToken.None`
convention already present on the post-commit enqueues.

## 2026-07-12 — External-collections scans get an authoritative status surface (#271); the SPA timeout is retired

**External Collections rows stay client-derived.** The SPA derives them from `GET
/api/v1/media-sources`: remote sources expose only sync-enabled libraries, so a non-empty `libraries` list is
equivalent to Blazor's `Libraries.Any(ShouldSyncItems)` filter. No second listing endpoint or fetch is needed.

The first scan-button implementation used a bounded optimistic timeout because collections locks had no HTTP
mirror. #271 replaces that temporary ceiling with the authoritative status contract below.

**Decision 1 — one family-global status endpoint, reading `IEntityLocker`.** New
`GET /api/v1/media-sources/collections-scan-status` (`MediaSourcesController` → `GetCollectionsScanStatus`
handler) returns one `CollectionsScanStatusResponseModel { family }` entry per media-source family
(`plex`/`jellyfin`/`emby`) whose collections lock is currently held, and only for active ones — the direct
counterpart to `GET /api/v1/libraries/scan-status`. It reads `IEntityLocker.Are{X}CollectionsLocked()` (the lock
*is* the running scan — the scan-collections controllers acquire it before enqueueing and the scanner releases
it on completion), analogous to how the library endpoint reads `IScannerProxyService.GetActiveScans()`. Two
deliberate shape differences from libraries: (a) **family-global, not per-source** — the collections lock takes
no source id (`LockPlexCollections()`), so an entry means *every* source of that family is scanning, matching
Blazor's all-rows-disabled behavior (per the PR #272 review note); (b) **no percent** — collections scans
expose only a boolean lock, not progress.

**Decision 2 — the SPA reconciles authoritatively; the fixed timeout is removed.** `useCollectionsScan` now
polls the new endpoint (seeding on mount, so a scan already running when the screen opens disables the buttons
immediately — the old timeout couldn't) and reconciles optimistic pending against the active-family set using
the **same `pruneGraceExpiredPending` grace-tick helper** the library hook uses (now generic over the pending
key type). A row shows "Scanning" when its family is in the active set **or** it has a still-in-grace optimistic
pending key. The grace window is kept (not the old wholesale timeout) to absorb the click→observed-active lag and
the fast-scan-between-polls race — the same bounded-pending discipline #232/#230 established for library scans.
`COLLECTIONS_PENDING_TIMEOUT_MS` is gone.

## 2026-07-11 — Blazor Server UI removed (#91 phase b)

The #91 phase (b) removal PR deletes the legacy Blazor Server UI now that the ChicoryTV SPA has parity
(all gates cleared: #145, #151/#152/#153/#155, #202, #207, #212/#213, #235 F9). The SPA is the only UI.

**Deleted.** `ErsatzTV/Pages/**` (all `.razor`, incl. `_Host.cshtml`, `FragmentNavigationBase.cs`,
`MultiSelectBase.cs`), `ErsatzTV/Shared/**` (all `.razor` + `_Favicons.cshtml`), `ErsatzTV/ViewModels/**`
(39 Blazor edit-form VMs), `ErsatzTV/Validators/**` (10 Blazor edit-VM FluentValidation validators),
`App.razor`, `_Imports.razor`, `ErsatzTV/Locals/Shared/**` + `ErsatzTV/Locals/Pages/**` (Blazor
localization resx — `ErsatzTV/Locals/Resources.*` is KEPT), `ErsatzTV/wwwroot/css/**` (site.css),
`ErsatzTV/wwwroot/lib/**` (jquery, jqueryui, sortablejs, hls, media-chrome, roboto), `libman.json`, and
`ErsatzTV.Tests/Pages/MultiSelectBaseTests.cs`.

**9 packages pruned** (from both `Directory.Packages.props` and `ErsatzTV/ErsatzTV.csproj`; each verified
to have zero remaining consumers after the Blazor deletion): **MudBlazor**, **Heron.MudCalendar**,
**Blazored.FluentValidation**, **BlazorSortable** — unambiguous Blazor UI; **MediatR.Courier.DependencyInjection**
— `ICourier` was consumed only by the deleted pages, and the app's `mediator.Publish` notification path is
plain MediatR (unaffected by the `AddCourier` removal); **Markdig**, **HtmlSanitizer**, **Chronic.Core**,
**NaturalSort.Extension** — verified zero non-Blazor consumers post-deletion.

**Startup surgical reduction.** Removed `AddRazorPages` (+`AuthorizeFolder("/")`), `AddServerSideBlazor`,
`AddMudServices`, `AddSortable`, `AddCourier`, the Blazor-attached `UseAuthentication`/`UseAuthorization`,
`MapBlazorHub`, and `MapFallbackToPage("/_Host")`. The former "blazor" `MapWhen` branch (lambda param
renamed `blazor`→`legacy`) is KEPT — it still co-hosts `MapControllers()`, `/docs` (Scalar), dev
`MapOpenApi()`, and the `LegacyUiRedirects` middleware. `MapFallbackToPage("/_Host")` is REPLACED by a
catch-all `endpoints.MapFallback(...)` that 302-redirects any unmatched path to `PathBase + "/app"`
EXCEPT paths under `/api`, `/artwork`, `/docs`, `/openapi` (those get a genuine 404, per #204's design).
**KEPT** (not removed): the OIDC/JWT/API-key SERVICE registrations (inert unless configured; real auth is
#197), `ConditionalIptvAuthorizeFilter` (`/iptv/*`), and `ApiKeyAuthorizationFilter` (mutating `/api/*`) —
per the #206 auth-posture sign-off (deleting the Blazor page challenged nothing beyond phase (a)).

**LegacyUiRedirects.** Added redirects for all 14 `/media/sources/*` routes → their `/app/libraries/*`
SPA screens (7 Tier-1 exact + 7 Tier-2 `{id}` patterns; the last Section-2 rows in
`blazor-route-parity.md`), and LIFTED the #204-era `/media/sources` forbidden-prefix guard (its Blazor
pages were replaced by #202's SPA screens). The forbidden-prefix guard now covers only `/api`, `/artwork`,
`/docs`, `/openapi`, `/iptv`, `/app`.

Also removed the now-dead ersatztv#25 razor-Sonar `<NoWarn>S6966;S3267;…</NoWarn>` line from
`ErsatzTV.csproj` — those Sonar rules only needed suppression in `.razor` `@code`; on `.cs` they run at
`suggestion` via `.editorconfig`, so removal is safe (closes part of #25's burn-down).

**Rollback.** The tag `blazor-final` was cut on the pre-removal `main` commit as the first step (see the
2026-07-11 "Pre-removal Blazor rollback tag `blazor-final` (#205)" entry above for the exact command +
restore path). Not a `v*` tag → no prod release build.

## 2026-07-12 — Live-E2E is a required step for API write-path handler changes (#303)

**A PR that changes an API write-path handler (a `POST`/`PUT`/`DELETE` `/api/*` command that mutates
state and reloads it through the read path) MUST include a live-E2E pass** — driving the real endpoint
or its SPA screen and confirming the mutation round-trips through a subsequent read — not only unit /
characterization tests. Rationale: this class has a **correlated blind spot** unit and characterization
tests share. A green fixed-point test passed while the write-path returned a production 500 because the
handler returned a *lazy* LanguageExt `Map` the test never enumerated (#229; reload-through-read-path
mechanics in `api-conventions.md` §7); the failure surfaces only when the result is materialised, which
the SPA does and the test did not. Live driving is the only reliable net for it.

Non-write-path (pure-SPA/read-only) and docs PRs don't need it. The requirement is auditable, not
silent: the PR/close comment states that live-E2E ran, or — for a non-write-path change — that it
wasn't required (the same stated-exemption discipline as the review skip rubric). Recipe +
"When live-E2E is required": `docs/e2e-local.md`. This formalizes the #229 lore bullet ("live E2E
remains the only net for this class") into a standing convention.

## 2026-07-12 — TopBar primary-action button: wire creates, drop the rest (#238)

The shell TopBar rendered a prominent top-right primary-action button (Plus icon) for **every** screen, but
only `SchedulesScreen` had ever subscribed to its `ctv:primary-action` event — so on every other screen the
button was **dead** (either a labelled no-op like "Save Changes"/"Add Channel", or, for the ~10 routes whose
`primaryAction` was `''`, a bare labelless "+"; the button rendered unconditionally). Issue #238 (from a #229
live-E2E finding, pre-existing since the TopBar's introduction).

**Decision — the Plus-icon button is a "create new item" affordance; keep+wire it only where that fits:**

- **TopBar renders the button only when the active route declares a non-empty `primaryAction`** (was:
  unconditional). This alone removes every empty-`''` dead "+".
- **WIRE** (8 list screens with a single unambiguous create flow) via a shared `usePrimaryAction(routeId,
  handler)` hook (`web/src/primaryAction.ts`), each delegating to the same top-level create handler its in-body
  control uses (`navigateToPath('/app/new-channel')`, `setEditing({kind:'new'})`, `navigateToPath('…/add')`,
  etc.): channels, schedules (refactored onto the hook), multiCollections, rerunCollections, traktLists,
  fillerPresets, ffmpegProfiles, watermarks.
- **DROP** (`primaryAction: ''`, no button) everywhere else, for one of four reasons: (1) the action isn't a
  create so the "+" is wrong and a correct in-body control already exists — editChannel (savebar), settings
  (savebar), guide (Jump to now), playouts (Reset all), logs/troubleshooting/blockPlayoutTroubleshooting
  (Refresh), playbackTroubleshooting (Play), yamlValidator (Validate); (2) ambiguous — collections (two create
  types behind tabs); (3) a silent no-op — builder ("Create Channel" is disabled until the form is valid),
  playlists (needs a group first); (4) semantically misplaced — dashboard (status page), libraries ("Scan" is
  per-library-row, no global target).

**Why not wire everything** (the SchedulesScreen precedent): the recon found every screen already carries a
correct, disabled-state-aware, context-aware in-body control, and several banner actions are unreachable
without refactoring handlers out from under early returns, or would render a silent no-op — reintroducing the
very dead-button class #238 fixes. Wiring only the single-create-flow screens gives one explainable rule
("primary button = create a new item on a list screen") and needs no risky refactors.

**Also fixed here:** the `apiKey` route's `primaryAction: 'Save key'` + its description/comment were stale
post-#295 (the screen displays the machine key + changes the local password; there is nothing to "save") —
relabelled to reflect the #295 reality. Convention + hook documented in `spa-conventions.md` §10. The
implicit route-label ⟺ screen-subscription coupling is the kind of thing #247 (shell extraction) will
formalize; #238 keeps it a documented convention guarded by a data-driven `App.test.tsx` test over the URL-navigating
create screens (a typo'd route id → the banner navigates nowhere → red). Refs #238 #247.
## 2026-07-13 — API versioning: the whole `/api` surface is mounted at `/api/v1`, additive-only after freeze (#286)

The #197 cold review's C1 **BLOCKER**: `/api/*` was entirely unversioned (`info.version` was cosmetic), so the
first breaking change would silently break the SPA and any external/MCP client with no negotiation path. This is
the Phase-2 contract-freeze gate — versioning can't be added compatibly *after* the contract ossifies, so it
lands before freeze.

**What changed.** Every route under `/api` was swept to `/api/v1` — all 251 controller route attributes, the ~24
`Location`-header literals, the scanner callback URL (`CallLibraryScannerHandler.GetBaseUrl`), and the
`Startup` request-log path literal. This is **uniform**: the machine JSON API, the browser-session auth surface
(`/api/v1/auth/*`, still `IgnoreApi`), the internal loopback callbacks (`/api/v1/scan/*`) and the scripted-build
surface (`/api/v1/scripted/*`) are all versioned, so there is no unversioned corner and the compat rewrite needs
no exclusion list. The OpenAPI `v1.json` (160 paths), `endpoint-index.md`, and the SPA (945 request literals +
its test mocks, incl. regex/positional URL parsers) were regenerated/swept in lockstep. **No wire-DTO or
status-code change** — only the path prefix moved.

**Legacy compat = an in-pipeline rewrite, NOT a redirect** (`ApiVersionRewriteMiddleware`, sequenced before
`UseRouting` in the API branch). A legacy caller hitting an unversioned `/api/foo` has its request *path*
rewritten to `/api/v1/foo` and continues in-pipeline — method, body, auth headers and query string all survive,
so curl / the future MCP server / bookmarked URLs keep working with no round-trip (a 307/308 redirect would have
been fragile for non-GET + custom-header clients). Rewritten (legacy) responses carry RFC 8594 `Deprecation: true`
+ `Link: </docs>; rel="deprecation"`, and a `Sunset` header when `Api:LegacyRoutesSunset` is configured. An
already-versioned path (`/api/v1/*`) passes through untouched; a future `/api/v2/*` is **not** forced back to v1
(the middleware only fills in a *missing* version).

**Freeze semantics (owner decisions):** once shipped, `/api/v1` is **additive-only** — new endpoints/optional
fields are fine; renaming/removing/retyping an existing one requires a new `/api/v2`, never an in-place break.
The legacy-rewrite compat shim has a **2-release sunset window** (owner-chosen) before removal; the actual removal
is a tracked Phase-3 follow-up, not this PR. Existing pre-freeze warts (e.g. channel `{id}` vs `{channelNumber}`,
the synthesized negative-id "(none)" group rows) are frozen as-is per their own prior decisions.

**Route-convention standardization (#286, owner-requested).** The leading-slash inconsistency (238 absolute
`"/api/…"` method routes vs 13 relative `"api/…"`) is resolved: the standard is a **leading-slash absolute route
on each method's `[Http*]` attribute, no class-level `[Route]`** — except the two controllers where many actions
share a parametrized prefix (`ScannerController` `{scanId}`, `ScriptedScheduleController` `{buildId}`, ~40
methods), which keep a leading-slash absolute **class** `[Route("/api/v1/…")]` with relative method segments (the
right tool for a shared prefix). Enforced by `ApiRouteVersioningTests`: it reflects over every `[ApiController]`
in `Controllers.Api`, computes each action's *effective* route (ASP.NET's class+method combination rule), and
asserts it matches `^/api/v\d+/` — so a new controller that drifts (relative or unversioned) fails CI, the
"fix-it-while-you're-in-the-file" gate the `dotnet format` rules use. Browser-nav endpoints deliberately outside
`/api` (e.g. `GET /auth/oidc/login`) are out of scope for the test. Docs: `api-conventions.md` §1/§9. Refs #286 #197.

## 2026-07-13 — Scheduling API hardening: null-name 500s, duplicate template items, unreachable 404 (#172)

Cleared the still-live findings from issue #172 (consolidated non-blocking nits from the #144 S1/S2
reviews). Most of the 2026-07-07 list had already been ratified deliberate (§8 "(none)" synthesized
rows; §3b deep-FK non-existence-check) or fixed since (the unauthenticated `/api/logs` +
`/api/troubleshoot/info` GETs now carry `[RequiresAuthentication]` per §9; the Trakt matched-items link
points at the live `/app/search`; `GET /api/search` already fans out via `Task.WhenAll`). Three were
genuinely live:

- **Null/empty `name` → 500 (10 handlers).** Create + Replace/Update handlers for Block, Template,
  DecoTemplate, Deco (8, all genuine 500s), plus `UpdateFFmpegProfile` (genuine 500; `CreateFFmpegProfile`
  was already guarded) and `CreatePlaylist` (its DTO coalesces `null`→`""`, so an empty-name persist, not a
  500) all did `if (request.Name.Length > 50)` on a client-nullable `string Name` → unhandled
  `NullReferenceException`. Fixed to `if (string.IsNullOrWhiteSpace(request.Name) || request.Name.Length >
  50)` — kills the NRE, and also rejects empty/whitespace names (matching the group-create handlers'
  `NotEmpty` behavior, closing a latent "block/template named ''" gap). Chose the one-line guard over
  refactoring each handler onto the `NotEmpty`/`NotLongerThan` combinator to keep the blast radius tiny and
  preserve each handler's existing error message + 422 mapping. Convention captured in `api-conventions.md`
  §3b handler-hardening checklist.
- **Exact-duplicate template items bypassed overlap validation.** `ReplaceTemplateItemsHandler`'s O(n²)
  overlap loop skipped on `item == otherItem`, but `BlockTemplateItem` is a `record`, so two value-identical
  items (same BlockId + StartTime → same computed EndTime) were value-equal and skipped — both persisted
  unvalidated. Switched to index-based iteration (`i != j`) so identical items at distinct positions are
  compared and register as a (self-)intersection → rejected 422. (The SPA's index-based check already caught
  this client-side; it was an API-only gap.)
- **Unreachable 404 on create-group actions.** `POST /api/blocks/groups` and `POST /api/templates/groups`
  declared `[ProducesResponseType(ProblemDetails, 404)]` copied from precedent, but a create has no parent
  lookup that can 404 (only 201/422). Trimmed — OpenAPI spec regenerated.

Deliberately **not** fixed (documented as accepted): the §8 "(none)" synthetic rows, the §3b deep-FK
non-existence-check, and the missing `Name=` on `PlayoutController` Create/Delete/Update (moot — the
"v1"-doc `OperationIdOpenApiTransformer` (#197 Bundle C) already synthesizes stable operationIds for
`Name=`-less ops, and adding `Name=` would risk renaming generated SPA client methods). Refs #172 #197.

## 2026-07-16 — Functional-E2E CI harness: advisory curl-contract job over an app booted from source (#299)

The manual live-E2E curl flows sessions had been re-running by hand (and leaving only as PR/issue
comments) are now a CI regression net. Two decisions shaped it:

**Boot from source + `dotnet run`, not the built image.** The only "E2E" in CI before this was the
smoke test in the `build` job, which runs against the *pushed* image — so it exists only on `main`/`v*`
(the image isn't built on PRs) and would test a stale image, not the PR's code. To gate PRs on the PR's
own code, the `functional-e2e` job builds the SPA + solution and launches `dotnet ErsatzTV.dll` via the
same `scripts/e2e-local.sh` used locally (parameterized with `ETV_BUILD_CONFIG=Release`). The assertions
live in `scripts/e2e-functional.sh`, so the identical harness runs by hand and in CI — which is the
point of the issue (stop re-deriving the flows each session).

**Advisory, not blocking — separate job, not a `build` dependency, not a required check.** Per the
issue's "a functional-E2E flake must not block the unit-test gate." A boot-the-app job has more moving
parts (background process, port, readiness wait) than a pure unit test, so it starts advisory and gets
promoted to a required check / `build` dependency once proven reliable — the same staged rollout the
`migrations` job used. SQLite is the default provider, so it needs no DB service container.

**Scope is curl-only and deterministic; the racy/interactive flows are explicitly deferred.** The first
cut asserts the legacy→SPA redirect sweep (+ `/api`/`/artwork` never-redirect exemption), the
auth/CSRF/security-stamp flow, the library-scan status contract (404/202/`scan-status`), and the
`If-Match`/412 round-trip — all exercisable without seeded media, ffmpeg-transcode, or a browser (an
empty local library still enqueues `202`; an empty collection drives the concurrency editor). The 409
"already-scanning" re-trigger (needs a long-running scan to be non-racy), the playout-build lock 409,
and the genuinely UI-interactive Playwright flows are deferred as #299 follow-ups rather than shipped
flaky. Assertions were written against a real running instance, not the source — which caught that
`/artwork/*` returns `400` (not the `404` a static read suggested); extend the harness the same way.

## 2026-07-16 — Optional advertised IPTV base URL (`iptv.base_url`) resolved centrally in the two generators (#340)

ErsatzTV's absolute IPTV URLs (M3U stream/logo/guide URLs, XMLTV `<icon>`/artwork) were always
derived from the incoming request's `Scheme`/`Host`/`PathBase`, so any client that fetched with a
host downstream consumers can't resolve (the historical Gitea #1 `localhost:8409` symptom) baked
that host into the output. #340 adds an **optional** advertised base URL to pin those URLs to a
fixed public origin. Several deliberate decisions shaped it:

**(a) Resolve the override centrally in the two generation handlers, via a pure Core helper — not
in the controller.** A new `ErsatzTV.Core/Iptv/AdvertisedBaseUrl.cs` exposes `TryParse(string) →
Option<(scheme, host, baseUrl)>` and `Resolve(configured, requestScheme, requestHost,
requestBaseUrl)`. `GetChannelPlaylistHandler` (M3U, via `ChannelPlaylist`) and
`GetChannelGuideHandler` (both XMLTV `{RequestBase}` substitution sites) call `Resolve` and use its
result instead of the raw request values. Keeping the logic in a pure, allocation-free Core helper
(not the thin controller) keeps controllers dumb, makes the parse/validate/resolve rules unit-testable
in isolation, and — because the fallback path returns the exact request-derived values — leaves the
M3U/XMLTV golden tests (`ChannelPlaylistGoldenTests`, `ChannelGuideGoldenTests`) untouched.

**(b) Validation rules, with blank/invalid → request-derived so "unset" is byte-identical.**
`TryParse` accepts only an **absolute http(s)** URL with **no credentials, query, or fragment**; it
**preserves the port and any path prefix** and **normalizes a trailing slash** off. Anything failing
these rules → `None`, and `Resolve` then falls back to the request-derived scheme/host/base. So an
unset or malformed value produces output byte-for-byte identical to today's request-derived behaviour
— the override is strictly opt-in and can never silently corrupt the default path.

**(c) A NEW `iptv` settings group, not folded under `xmltv`.** The base URL affects **both** the M3U
playlist and the XMLTV guide, so it does not belong under the existing XMLTV-only settings. `GET`/`PUT
/api/v1/settings/iptv` on `SettingsController` (tier `[RequiresAuthentication]`) with body `{ baseUrl }`,
backed by `GetIptvSettings`/`UpdateIptvSettings` handlers + `IptvSettingsViewModel` /
`IptvSettingsResponseModel` / `UpdateIptvSettingsRequest`, and a new "IPTV" section on the SPA Settings
screen. Follows the existing settings GET/PUT pattern — no new API convention.

**(d) Blank clears the key; non-blank malformed → 422.** A blank/whitespace `baseUrl` on PUT
**deletes** the `ConfigElement` (reverting to request-derived); a non-blank value that fails
`AdvertisedBaseUrl.TryParse` is rejected with **422** rather than being silently stored and ignored at
generation time — the error surfaces at the point of configuration.

**(e) Scoped to M3U + XMLTV, deliberately NOT HDHomeRun.** #340 covers only the M3U playlist and XMLTV
guide generators. The HDHomeRun lineup URLs still echo the request host; extending the override there
was explicitly out of scope.

**(f) Distinct from `ETV_BASE_URL`.** The `ETV_BASE_URL` environment variable only sets the ASP.NET
Core `PathBase` (request routing/prefix); it does not advertise a scheme+host. `iptv.base_url` is the
separate, DB-stored (`ConfigElementKey.IptvBaseUrl`, **no EF migration**) advertised origin for IPTV
output. See `docs/m3u-xmltv.md` → "IPTV base URL (#340)".

## 2026-07-16 — Auto-tuning enumerates via EF, persists via SmartCollection; additive coexistence (#69)

Auto-tuning (#69) generates channels from library metadata (TV Show / TV Genre / Movie Genre).
Enumeration for the preview uses EF distinct+count queries (exact counts drive the min-items
threshold and preview display); each created channel is backed by a newly-created **SmartCollection**
(live Lucene query) so channels keep tracking the library as it grows. Query authorship is
server-side only — the client passes `{axis, value}`, never a Lucene string. Coexistence is additive:
the batch gets a reserved starting channel number (skipping taken numbers), a proposed channel whose
name already exists is flagged and de-selected by default, and existing channels are never mutated.
Bulk create loops the #63 `CreateChannelFromLineup` primitive via `ISender` and returns a per-channel
Created/Skipped/Failed outcome. Known MVP limitation: the generated SmartCollection is named after the
channel; a name collision with an existing SmartCollection surfaces as a per-channel Failed outcome.

## 2026-07-16 — Per-playout reshuffle = scoped Reset build; seed surfaced (#71)

- The shuffle seed (`Playout.Seed`) + per-collection `CollectionEnumeratorState` already persist a stable
  shuffled order across rebuilds. #71's real gap was a **user-triggered per-playout reshuffle** (a Classic
  playout's seed is otherwise only reseeded by a full Reset, and `reset-all` uses `Refresh` for Classic, so
  it never reseeds Classic) plus visibility.
- `POST /api/v1/playouts/{id}/reshuffle` enqueues `BuildPlayout(id, PlayoutBuildMode.Reset)` — Reset already
  reseeds + clears anchors/rerun-history + rebuilds. Named `/reshuffle` (not `/reset`) to (a) match user
  intent and (b) avoid the "reset-one reseeds Classic while reset-all refreshes Classic" naming clash. It is
  deliberately more aggressive than `reset-all` for Classic: an explicit single-channel action rolls a new
  order; the bulk action stays non-disruptive.
- `Playout.Seed` is surfaced on the playout list + detail DTOs so the SPA can show it — its purpose is
  **visible confirmation** (the seed changes after a reshuffle).