Adds the shared optimistic-concurrency contract so a stale second tab can no longer
silently overwrite a fresher edit. PR1 lands the infra + the Block reference aggregate;
PRs 2–4 fan the same recipe across the other 8 roots (design: #253#issuecomment-8472).
Contract
- `IVersionedAggregate` (`int Version`) on all 9 replace-all roots (ProgramSchedule,
Block, Template, DecoTemplate, Playlist, Collection, Playout, MultiCollection,
RerunCollection), EF-mapped `.IsConcurrencyToken()`; one dual-provider migration
`AddAggregateVersions` (nullable:false, default 0).
- Strong `ETag` of `Version` on the aggregate GET; `If-Match` on the PUT; mismatch →
412 (distinct from the §3a 409 build-lock guard). Successful PUT returns the new ETag.
- `PreconditionFailedError : BaseError` → 412 in `ApiResults.ToErrorResult`;
`ConcurrencyHeaders.ParseIfMatch/SetETag`; malformed If-Match → 400; `*`/absent =
Phase-1 force-write.
Block reference wiring
- Handler: standalone `Either` via `CheckVersion` AFTER validation (never through
`Apply`, which Join()-flattens the subtype to 422), unconditional `Version++`,
`SaveChangesWithConcurrencyGuard` backstop (DbUpdateConcurrencyException → 412).
- `BlockViewModel.Version` (header-only, not echoed in the body); controller sets the
ETag on GET items and on the successful PUT.
- SPA: `client.requestWithMeta` seam; `blocks.getBlockItemsWithMeta` + `replaceBlock`
If-Match/ETag round-trip; `BlockEditor` holds the ETag, sends If-Match, and on 412
opens a blocking "changed elsewhere — reload" dialog.
Tests
- Handler contract tests: stale-If-Match → 412 (no mutation), matching/absent → success
+ bump, no-op save still bumps, and a two-context racing save → 412; proven
non-vacuous (drop `.IsConcurrencyToken()` → the race test fails).
- Controller tests: malformed If-Match → 400, If-Match threaded to the command, ETag on
GET/PUT, 412 passthrough. SPA: requestWithMeta ETag, replaceBlock If-Match, 412 dialog.
Docs: api-conventions §7a, spa-conventions §4a, domain-model glossary, decisions log.
Refs #253
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* start to add program schedule alternates
* edit days of the week
* editor improvements
* save changes
* build playouts using alternate schedules
* reset playout as needed
* add priority message
* starting database redesign
* set season and episode numbers
* use datetimes in db (utc); update movie metadata
* get movie cards from new table
* copy show/episode metadata
* remove old movie metadata type
* rename new movie metadata type
* code cleanup
* start to remove old television classes
* remove old television tables from database
* fix playout building
* fix collection views
* fix show/season views
* clean up movie metadata table
* fix scanner tests
* add libraries ui
* code cleanup
* fix movie scanning/metadata
* add library scan button to ui
* delete library path from ui
* temp disable movie scanning
* remove orphan media items and prevent duplicate paths
* attach artwork to metadata
* fix split show/season display
* fix television artwork
* store year distinct from release date
* fix collections ui
* code cleanup
* add library paths from ui
* fix adding to collections from ui
* fix schedule items loading
* schedule editing works again
* remove some todos
* more cleanup
* fix unit tests
* fix episode sorting
* fix deleting show library paths
* remove unused class
* fix playout list in ui
* fix log viewer
* start to use version/file instead of statistics
* clean up old columns
* fix playout display (time zone)
* fix playback
* fix channel guide time zone
* cascade more deletes
* fix compiler warnings
* fix adding new seasons
* use artwork for channel logo
* clean cache folder on startup (move channel logos, delete everything else)
* log database migration
* update homepage docs for libraries
* fix adding new channel with logo
* fix episode numbers in epg
timothyandClaude Opus 4.8