docs(901): the whitespace collapse belongs to the PRIMITIVE, so it belongs to both text pins

`mechanics:` opened with a universal — "a residual read off one of them does not
transfer to the others" — and then attributed the collapse-whitespace-inside-a-string
residual to `_normalise_lines` alone. It does transfer, between exactly the two pins
that sentence separates: `_normalise_lines` is `_normalise` applied per line
(`scripts/tests/test_image_build_delegates_the_spa_suite.py:327`), and the stage-command
pin calls `_normalise` directly (lines 386/389, compared at line 586), so it cannot see a
whitespace change inside a quoted shell string either. For SHELL text that is the more
consequential of the two residuals, which is the opposite of what the old ordering
implied.

The sentence now says NEED NOT transfer, names the one that does, and puts the
string-literal blindness on `_normalise` where it originates. The vite-only fact that
survives is the blank-line drop, and the claim that the test STATES its residual is
narrowed to the vite test, which is the only one of the two that does.

The hole is dormant rather than live — no entry in `PINNED_STAGE_COMMANDS` carries a
quote character — but the defect was the prose universal, which the record's own rule
("a pin also declares its NORMALISATION and what the normalisation cannot see") is what
this paragraph exists to demonstrate. This is the third finding read off this one
sentence: `b8dc321af` corrected its fault-message half and `4d5bd0dbb` its
outcome-claim half.

TWO OBLIGATIONS ARE OWED to the closing record, both blocked on #885 (open, so this
branch does not touch `scripts/tests/`), and both freed together when it closes:

1. The `CLAIMS` entry in `scripts/tests/mutation_manifest.py` for the hook-preamble
   selector — target `.claude/hooks/decisions-guard.sh`, clause = the canonical sink
   assignment, replacement = that line plus the `eval` spelling, proof = a
   `test_hook_fire_log.py` node, outcome=GREEN with the mandatory
   `reach_replacement`/`reach_expect`. Until then `mechanics:` states the SELECTOR as a
   structural fact and makes no outcome claim (`4d5bd0dbb`).

2. The comment at `scripts/tests/test_hook_fire_log.py:153-154`, which ends "this arm's
   errors are refusals, never acceptances". The structural fact this record ships — the
   compared set is the non-comment-led lines containing the literal `ETV_HOOK_FIRE_LIB`,
   so a reassignment that never spells the literal is outside the selection — is an
   ACCEPTANCE by that arm, and the same comment block concedes the class five lines later
   ("so it is an acceptance hole, not only a stricter refusal"). The sentence is owed a
   correction; the record documents the residual beside it in the meantime.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015QqCpYFsKgnAnx6jVwrKiV

docs/decisions/records/testing/guard-pins-the-artifact-not-a-shape.md

@@ -7,7 +7,7 @@ supersedes: none
 superseded-by: none
 rule: 'A predicate that decides something by matching a SHAPE inside an artifact whose GRAMMAR it does not implement pins the artifact WHOLE instead — the whole file, or a whole named span, compared for equality under a STATED normalisation. The boundary is the grammar and never the file type: shell source, a workflow `run:` body, TOML, YAML, a jq expression and JSON5 all qualify, and a shape matched over the OUTPUT of a real parser for that grammar does not. Extracting a `run:` value with a real YAML parser and then matching shell inside it IS in the class, because the shell is the unparsed half. THE PIN IS THE DEFAULT FOR A NEW PREDICATE; REJECTED is the alternative of writing the shape-matcher and pinning only once it has been defeated. The defeat a remedy policy waits for is a false GREEN, so it is found by a reviewer or by an incident and never by the guard: "not defeated yet" is a statement about who has looked, not about the input space. A SHAPE-MATCHER IS THE EXCEPTION, and its argument carries FOUR things, written where the predicate is and re-read whenever a clause of it is widened. (1) The GRAMMAR named, and the parser that implements it — if the shape is matched over a real parse there is no exception to write. (2) The INPUT SPACE as a CLOSED enumeration with the reason it is closed: a generator whose output form is fixed, or a canonicaliser the guard itself runs. A list of the spellings the author thought of is not that reason, and is the thing that was defeated nine, seven and five times. (3) The FAILURE DIRECTION measured rather than asserted: each defeat the matcher claims to catch is a DECLARED, executed mutation under `testing.mutation-claims-are-executed`, because a shape-matcher''s miss is a false green and an unrun claim about a fail direction is not evidence. (4) WHAT IT BUYS over the pin, priced in a cost the pin actually charges — the artifact is edited routinely or written by tooling, so a pin would redden as background noise and train its readers to ignore it; or the artifact''s population is DISCOVERED rather than fixed, so there is nothing to pin. Fewer than four is a refusal, and neither elegance nor an unwillingness to update a constant is one of the four. TWO OTHER BARS ARE REJECTED for this exception: a NUMERIC one ("survives N adversarial spellings"), which measures the reviewer''s imagination rather than the input space and would have licensed the parser above through most of nine rounds; and a REVIEWER SIGN-OFF, which makes the exception depend on the very signal the threshold below says arrives late. THE THRESHOLD for withdrawing a shape-matcher already shipped is not a count of spellings: it is the moment the NEXT spelling is found by the REVIEWER rather than by the author, which is evidence that the author''s model of the input space is not the input space. TWO RIDERS, both measured. A pin assumes it is pinning the artifact that still DECIDES — ask what else could decide this and whether the pin would still match: another FILE that outranks it, another OCCURRENCE in the same file, another WORKFLOW, or a HOOK the pinned command invokes. And WIDENING A CLAUSE RETIRES THE PROOFS CALIBRATED AGAINST THE NARROW ONE: a canary asserting that a finer mutation still SURVIVES has as its precondition that the guard is deliberately coarse there, so widening the main clause turns the canary into a tautology, which reads exactly like a passing proof — re-derive every proof calibrated against the narrow clause in the same commit that widens it. THE COST IS STATED RATHER THAN DISCOVERED LATER: any edit to a pinned artifact reddens, and the pin is updated deliberately in the same commit, with a reason. That red IS the review trigger the pin exists to be. A pin also declares its NORMALISATION and what the normalisation cannot see, because "pinned whole" invites a reader to assume byte equality.'
 signals: 'pin the artifact whole · shape-matcher is the exception that argues for itself · the boundary is the grammar not the file type · predicate does not implement the grammar it parses · defeated by the next spelling · the reviewer found the next spelling · false RED versus false GREEN · nine defects one mechanism · seven respellings of a partial config match · five spellings of a lexical preamble rule · the four-part exception argument: grammar and parser, closed input space, measured fail direction, what it buys · authority moves where the pin is not looking · an outranking config file · a decoy occurrence · an npm lifecycle hook · widening a clause retires its own canary · a survived-clause canary becomes a tautology · a pin declares its normalisation · instances: `ci.image-build-delegates-the-spa-suite`, `process.hook-resolves-inputs-from-repo-root` · paths: `scripts/tests/test_image_build_delegates_the_spa_suite.py`, `scripts/tests/test_hook_fire_log.py`, `docs/guard-inventory.md`, `docs/defect-shapes-773.md` · issues: #901, #887, #891, #774, #790, #881, #773'
-mechanics: 'Two worked pins. `scripts/tests/test_image_build_delegates_the_spa_suite.py` pins command TEXT (`PINNED_STAGE_COMMANDS`), `web/package.json`''s script map (`PINNED_PACKAGE_SCRIPTS`) and `web/vite.config.ts` entire (`PINNED_VITE_CONFIG`), the last two after a SELECTION and then a partial match were defeated. The three normalise DIFFERENTLY, so a residual read off one of them does not transfer to the others: the stage commands are compared after line continuations are joined and whitespace within each command is collapsed (`_normalise`), so a reflow is free and a line boundary is not; the script map is dict equality over parsed JSON, so the file''s own formatting and key ORDER are free while every script body is exact; and of the three only `PINNED_VITE_CONFIG` runs through `_normalise_lines`, which drops blank lines and collapses whitespace within a line — including inside a string literal, the residual that test states rather than claiming byte equality. `scripts/tests/test_hook_fire_log.py` pins the hook preamble''s two lines byte for byte (`CANONICAL_SINK_ASSIGNMENT`, `CANONICAL_SINK_SOURCE`), named once so the checker, the mutation proofs and the hooks cannot come to mean different strings — but its normalisation is a SELECTION, and the rule above obliges this record to say what that selection cannot see, because the pin itself does not. The compared set is the lines that contain the literal `ETV_HOOK_FIRE_LIB` and are not comment-led, so the pin reaches exactly the two preamble lines and nothing else in the file: a later reassignment of that variable which never spells the literal — one composed at runtime and `eval`ed, say — is outside the selection, and therefore outside the pin, however the checker then behaves. Byte-identity WITHIN a selection is not byte-identity over the file — the pin''s reach ends where its selector does. That is stated here as a structural fact about the selector and NOT as a measured checker outcome, because an outcome claim about a mutation is a declared, harness-executed `CLAIMS` entry under `testing.mutation-claims-are-executed` or it is not written, wherever it is written — this record included. The residual is #891 code and predates this record; stating it is this record''s own rule applied to one of its own worked pins. Each of the three image-build pins faults with a request for the reason in the same commit, and two of them name the CONSTANT to update (`PINNED_STAGE_COMMANDS`, `PINNED_VITE_CONFIG`) while the script-map fault names the FILE and prints both maps. The hook-preamble fault asks for neither: it reports the divergent lines, since the two canonical strings ARE what a deliberate change edits.'
+mechanics: 'Two worked pins. `scripts/tests/test_image_build_delegates_the_spa_suite.py` pins command TEXT (`PINNED_STAGE_COMMANDS`), `web/package.json`''s script map (`PINNED_PACKAGE_SCRIPTS`) and `web/vite.config.ts` entire (`PINNED_VITE_CONFIG`), the last two after a SELECTION and then a partial match were defeated. The three normalise DIFFERENTLY, so a residual read off one of them NEED NOT transfer to the others — and one of them does transfer, because two share a primitive: the stage commands are compared after line continuations are joined and whitespace within each command is collapsed (`_normalise`), so a reflow is free and a line boundary is not; the script map is dict equality over parsed JSON, so the file''s own formatting and key ORDER are free while every script body is exact; and of the three only `PINNED_VITE_CONFIG` runs through `_normalise_lines`, which additionally drops blank lines. `_normalise_lines` IS `_normalise` applied per line, so the whitespace collapse — including inside a QUOTED STRING, where it can change meaning — belongs to both TEXT pins and not to the vite one alone; of the two only the vite test states it, in place of claiming byte equality, which is what the rule above asks of a pin. `scripts/tests/test_hook_fire_log.py` pins the hook preamble''s two lines byte for byte (`CANONICAL_SINK_ASSIGNMENT`, `CANONICAL_SINK_SOURCE`), named once so the checker, the mutation proofs and the hooks cannot come to mean different strings — but its normalisation is a SELECTION, and the rule above obliges this record to say what that selection cannot see, because the pin itself does not. The compared set is the lines that contain the literal `ETV_HOOK_FIRE_LIB` and are not comment-led, so the pin reaches exactly the two preamble lines and nothing else in the file: a later reassignment of that variable which never spells the literal — one composed at runtime and `eval`ed, say — is outside the selection, and therefore outside the pin, however the checker then behaves. Byte-identity WITHIN a selection is not byte-identity over the file — the pin''s reach ends where its selector does. That is stated here as a structural fact about the selector and NOT as a measured checker outcome, because an outcome claim about a mutation is a declared, harness-executed `CLAIMS` entry under `testing.mutation-claims-are-executed` or it is not written, wherever it is written — this record included. The residual is #891 code and predates this record; stating it is this record''s own rule applied to one of its own worked pins. Each of the three image-build pins faults with a request for the reason in the same commit, and two of them name the CONSTANT to update (`PINNED_STAGE_COMMANDS`, `PINNED_VITE_CONFIG`) while the script-map fault names the FILE and prints both maps. The hook-preamble fault asks for neither: it reports the divergent lines, since the two canonical strings ARE what a deliberate change edits.'
 ---
 
 **The class, and what approximating it costs.** A predicate over an artifact with a grammar is a