feat(#1740): require-fs-op-fallback production AST rule + Windows transient-lock retry (Phase 6) (#1742)

* feat(#1740): require-fs-op-fallback production AST rule + Windows transient-lock retry (Phase 6)

ADR-1703 Phase 6 of the cross-platform portability epic (#1702). Adds the
second production-code portability AST rule + the ADR-mandated glob expansion
to bin/install.js and scripts/build-hooks.js.

- eslint-rules/require-fs-op-fallback.cjs: flags an unguarded fs.rename /
  fs.renameSync (the atomic-publish primitive named first in
  DEFECT.WINDOWS-FS-OPS.symptom) that is NOT inside a try/catch whose handler
  references a transient errno ('EPERM'/'EBUSY'/'EACCES' or a *RETRY_ERRNOS
  set) AND NOT behind a Windows platform guard. A catch that silently swallows
  or cleans-up-and-rethrows without an errno check does NOT satisfy the
  defect's 'never silently swallow' clause. copyFile/unlink are deliberately
  not flagged (they are the fallback primitives per the defect's own
  fix-forward). Scope narrowed to rename per Phase 5's precision discipline;
  documented on #1740.

- src/shell-command-projection.cts: export retryRenameSync(from, to) — the
  drop-in bounded-retry helper over the existing atomicRenameWithRetry.

- 27 bare fs.renameSync sites across 11 modules routed through retryRenameSync
  (capability-lifecycle/lock/source, installer-migrations, milestone, phase,
  planning-workspace, roadmap-upgrade, runtime-hooks-surface, state,
  workstream). Idempotent on POSIX; resilient to AV/indexer transient locks
  on Windows.

- eslint.config.mjs: register rule at error on src/**/*.cts; new focused
  portability-rules block covering bin/install.js + scripts/build-hooks.js
  (ADR-1703 L124-126 glob expansion — both files are compliant: zero
  rename violations).

- tests: 15-case RuleTester suite; portability-rule-disable-ban extended
  (PROTECTED_RULES + scans bin/install.js/build-hooks.js with shebang
  handling); ci-test-scope portability-lint selection rule.

- CONTEXT.md DEFECT.WINDOWS-FS-OPS predicate rewritten to point at the rule;
  docs/contributing/cross-platform-portability-rules.md reference + how-to.

Closes #1740

* chore(#1740): backfill changeset pr:1742

* fix(#1740): tighten require-fs-op-fallback precision (codex review HIGH-1/HIGH-2)

Addresses two false-negative findings from the codex (gpt-5.5/high)
adversarial review of PR #1742:

HIGH-1 — a catch that REFERENCES a transient errno but only rethrows (no
retry/fallback) was marked compliant. The DEFECT.WINDOWS-FS-OPS fix-forward
requires retry, not just recognition. Fix: catchHandlerHasRetrySignal now
requires a loop `continue` backedge OR a `return <call>` delegation; a bare
rethrow is flagged. The misleading `/* retry logic */` valid test is replaced
with a real retry loop, and the rethrow-only shape is added as invalid.

HIGH-2 — the nested-try ancestor walk treated an OUTER errno-catch as
protecting the rename even when an INNER catch intercepted/swallowed the error
(the outer catch is unreachable). Fix: isInsideTransientErrnoTryCatch now stops
at the NEAREST enclosing TryStatement WITH A CATCH HANDLER whose block contains
the rename (try-finally is skipped — it doesn't catch); outer catches are no
longer consulted. The unsound nested-try valid test is converted to invalid,
and a try-finally-skipped valid case is added.

Verified: 17 RuleTester cases pass; zero new production violations (the 27
fixed sites use retryRenameSync; the real retry loops — atomicRenameWithRetry,
capability-ledger/consent, build-hooks — remain compliant via continue/errno);
lint:ci green; disable-ban + vocab-drift green.

---------

Co-authored-by: review-bot <review-bot@gsd>

scripts/ci-test-scope.cjs

@@ -214,17 +214,35 @@ const RULES = [
     ],
   },
   {
-    name: 'configuration',
-    match: path => ['config', 'configuration', 'model-catalog', 'model-profile'].some(k => path.includes(k)),
+     name: 'configuration',
+     match: path => ['config', 'configuration', 'model-catalog', 'model-profile'].some(k => path.includes(k)),
+     tests: [
+       'tests/config.test.cjs',
+       'tests/config-get-default.test.cjs',
+       'tests/configuration-migrate-config.test.cjs',
+       'tests/model-catalog-runtime-defaults.test.cjs',
+       'tests/model-profiles.test.cjs',
+     ],
+   },
+  {
+    // ADR-1703 portability lint surface. Editing a rule, the shared vocab/guard
+    // helpers, or the eslint config that wires them must re-run the rule suites
+    // + the disable-ban. The disable-ban also scans bin/install.js and
+    // scripts/build-hooks.js (the Phase 6 glob-expansion surface), so changes
+    // to those files re-run it too.
+    name: 'portability lint rules (ADR-1703)',
+    match: path => path.startsWith('eslint-rules/') ||
+      path === 'eslint.config.mjs' ||
+      path === 'bin/install.js' ||
+      path === 'scripts/build-hooks.js',
     tests: [
-      'tests/config.test.cjs',
-      'tests/config-get-default.test.cjs',
-      'tests/configuration-migrate-config.test.cjs',
-      'tests/model-catalog-runtime-defaults.test.cjs',
-      'tests/model-profiles.test.cjs',
+      'tests/portability-rule-disable-ban.test.cjs',
+      'tests/portability-vocab-drift.test.cjs',
+      'tests/require-fs-op-fallback.rule.test.cjs',
+      'tests/normalize-path-in-content.rule.test.cjs',
     ],
   },
-];
+ ];
 
 function usage() {
   return [