fix(#934): reapply verifier handles missing pristine baseline post-rename (#937)

* fix(#934): reapply verifier handles missing pristine baseline post-rename

Gap 1 (verify-reapply-patches.cjs): when backup-meta.json records a
pristine_hash for a file but gsd-pristine/ has no corresponding snapshot
on disk, the verifier fell to over-broad mode and produced false
FAIL_USER_LINES_MISSING. Fix: return advisory OK_NO_BASELINE (non-blocking,
exit 0) so the verifier does not block on files it cannot reason about.

Gap 2 (new migration 004): migration 003 removed legacy get-shit-done/
runtime files but left gsd-pristine/get-shit-done/ orphan snapshots in
place. Those stale snapshots referenced get-shit-done/... key paths that
no longer match the active gsd-core/... layout. Fix: add migration
004-prune-stale-pristine-get-shit-done (NOT editing 003, preserving its
checksum — ref #670 guard) to remove all files under
gsd-pristine/get-shit-done/ as GSD-managed pristine snapshots.

Includes tests: bug-934 OK_NO_BASELINE assertions in the verifier test,
new installer-migration-prune-stale-pristine.test.cjs, updated
installer-migrations baseline-lock checksum for 004.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* fix(#934): rename migration to satisfy legacy-name guard + mark intentional path refs

Rename src/installer-migrations/004-prune-stale-pristine-get-shit-done.cts
→ 004-prune-stale-pristine-snapshots.cts so the filename no longer contains the
forbidden token.  Update .gitignore and eslint.config.mjs to track the new built
path.  Add gsd-allow-legacy-name markers to the remaining intentional uses of the
legacy path string in the migration body (lines 3 and 100) and in tests
(installer-migration-prune-stale-pristine.test.cjs lines 202 and 226; and the
baseline-lock key in installer-migrations.test.cjs:1469).  Update the baseline
checksum for migration 2026-06-09-prune-stale-pristine-get-shit-done to reflect
the two new marker comments added to its body.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
(cherry picked from commit 74a121bb4f)

tests/installer-migrations.test.cjs

@@ -1465,6 +1465,9 @@ test('shipped installer-migration checksums are locked to a committed baseline (
       'sha256:5ce55294aa02f25758f604a569c899a6d2d060299189f5f447f68d8033157058',
     '2026-06-02-rename-get-shit-done-to-gsd-core':
       'sha256:3a9f1d97f64097fb313203d19c6d93a187a38df61dd299afa5eef73e16124e95',
+    // Migration 004: prune stale gsd-pristine/get-shit-done/ snapshots (#934) // gsd-allow-legacy-name
+    '2026-06-09-prune-stale-pristine-get-shit-done': // gsd-allow-legacy-name
+      'sha256:6555dd044659276fbc204e81793cd92c5315d54e7316bcdd82d2c98d15a7e9e8',
   };
 
   const { DEFAULT_MIGRATIONS_DIR, migrationChecksum: computeChecksum } = require('../gsd-core/bin/lib/installer-migrations.cjs');