fix(spec): correct the changeset's dist claim for spec-changes.ts (#17152)

Round 4, ruled in-seat (ESCALATE resolved as a bounded patch, comment 5854106957 on
#17152; blocking item: at-tier record 5854088720 on PR #20181, item 1).

The changeset said spec-changes.ts's rationale .describe() text does not ship to
dist, with "zero hits either wording". It does: SpecMigratedSchema is a root-entry
export (migrations/index.ts:38, api-surface/root.json:150), and a real build of this
head confirms the corrected wording is present, with a positive-control hit in the
same file, in dist/index.js, dist/index.mjs and both dist/browser/* bundles -- 1 hit
each for the new sentence and the lit control "The D3 semantic-migration id.", 0 for
the old sentence. It is absent from dist/index.d.ts and dist/index.d.mts (confirmed
readable via the SpecMigratedSchema positive control, 3 hits each) because .describe()
string arguments are runtime values TypeScript's declaration emit does not carry.

Reworded to say it ships in the runtime bundles, not in the .d.ts, json-schema/** or
spec-changes.json, and dropped "zero hits either wording" for that file. Kept the
registry.ts clause on its own terms (measured: its docblock still does not ship to
dist at this head; unchanged from before). No other wording moved.

Author: claude

.changeset/17152-d3-per-family-house-rule.md

@@ -8,4 +8,4 @@ Clause-②: no
 
 The shape ruled superseded (director-seat class-one self-adjudication on #17152, authority: the maintainer's ruling on #15954) was stated in several places, each in its own words: `types.ts`'s module docblock said "breaks with no lossless mapping"; `types.ts`'s `SemanticMigration`/`MigrationStep`/`reason` doc comments said "A non-lossless change", "Why this is not losslessly convertible" and "Non-lossless changes authored for this major"; `registry.ts`'s module docblock said "the non-lossless residue D2 could not express"; and `spec-changes.ts`'s `SpecMigratedSchema` said "A semantic (non-lossless) migration" with a `rationale` `.describe()` of "Why it is not losslessly convertible". All are corrected to the same meaning: a D3 entry is owed per retirement family regardless of whether D2 is lossless, and `reason`/`rationale` now say why the consumer still owes a judgment rather than why the change cannot be losslessly converted.
 
-No entry, gate or runtime behaviour changes; this is a doc-comment correction, filed as `patch` because the `types.ts` prose ships verbatim into the published `dist/index.d.ts` / `dist/index.d.mts` (measured: `grep` after a real build finds each corrected sentence there, with `MigrationStep` and `MIGRATION_SUPPORT_FLOOR` as positive controls proving `dist` is readable). `registry.ts`'s docblock and `spec-changes.ts`'s `.describe()` text do not ship to `dist`, `json-schema/**` or `spec-changes.json` (same positive controls, zero hits either wording, and `check:spec-changes` / `check:upgrade-guide` / `check:authorable-surface` all report their generated artifacts unchanged) but are corrected for the same reason — each is prose the card and the ruling target.
+No entry, gate or runtime behaviour changes; this is a doc-comment correction, filed as `patch` because the `types.ts` prose ships verbatim into the published `dist/index.d.ts` / `dist/index.d.mts` (measured: `grep` after a real build finds each corrected sentence there, with `MigrationStep` and `MIGRATION_SUPPORT_FLOOR` as positive controls proving `dist` is readable). `registry.ts`'s docblock does not ship to `dist` at this head (same positive controls, zero hits either wording). `spec-changes.ts`'s `.describe()` text ships in the runtime bundles (`dist/index.js`, `dist/index.mjs`, `dist/browser/*`), not in the `.d.ts`, `json-schema/**` or `spec-changes.json` (measured the same way, with `SpecMigratedSchema` as the `.d.ts` positive control). `check:spec-changes` / `check:upgrade-guide` / `check:authorable-surface` all report their generated artifacts unchanged. Both are corrected for the same reason — each is prose the card and the ruling target.