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>

eslint.config.mjs

@@ -23,6 +23,7 @@ import noHardcodedTmp from './eslint-rules/no-hardcoded-tmp.cjs';
 import noBareNpmExec from './eslint-rules/no-bare-npm-exec.cjs';
 import requireUserprofileWithHome from './eslint-rules/require-userprofile-with-home.cjs';
 import normalizePathInContent from './eslint-rules/normalize-path-in-content.cjs';
+import requireFsOpFallback from './eslint-rules/require-fs-op-fallback.cjs';
 
 const localPlugin = {
   rules: {
@@ -40,6 +41,7 @@ const localPlugin = {
     'no-bare-npm-exec': noBareNpmExec,
     'require-userprofile-with-home': requireUserprofileWithHome,
     'normalize-path-in-content': normalizePathInContent,
+    'require-fs-op-fallback': requireFsOpFallback,
   },
 };
 
@@ -224,6 +226,36 @@ export default tseslint.config(
       // excluded; content heuristic tightened to genuine reference/config-dir
       // markers). See RULESET.CONTENT-PATH-NORMALIZATION in CONTEXT.md.
       'local/normalize-path-in-content': 'error',
+      // ADR-1703 Phase 6: flag an unguarded fs.rename/fs.renameSync (the
+      // atomic-publish primitive) that lacks a transient-errno fallback
+      // (EPERM/EBUSY/EACCES retry or a Windows platform guard). See
+      // DEFECT.WINDOWS-FS-OPS in CONTEXT.md.
+      'local/require-fs-op-fallback': 'error',
+    },
+  },
+
+  // ── bin/install.js + scripts/build-hooks.js — ADR-1703 Phase 6 glob expansion ─
+  // The top-level `bin/install.js` (generated installer) and `scripts/build-hooks.js`
+  // (the build-side atomic-replace helper) are the two production surfaces named by
+  // DEFECT.WINDOWS-FS-OPS that were NOT covered by the src/**/*.cts / gsd-core/bin/**/*.cjs
+  // globs (ADR-1703 L124-126). This block brings them under the two production
+  // portability rules. It deliberately does NOT apply the full js.recommended set —
+  // bin/install.js is ~12k lines of generated code; the ADR's mandate is the
+  // portability defect surface, not a broader generated-code style sweep.
+  {
+    files: ['bin/install.js', 'scripts/build-hooks.js'],
+    plugins: {
+      local: localPlugin,
+    },
+    languageOptions: {
+      sourceType: 'commonjs',
+      globals: {
+        ...globals.node,
+      },
+    },
+    rules: {
+      'local/normalize-path-in-content': 'error',
+      'local/require-fs-op-fallback': 'error',
     },
   },