Merge origin/main (v1.65.0.0 fork port wave 2) into test-evals-ci-speedup

Second overlapping-wave merge; resolutions compose intent:

- TEST_ROOTS: ours is the superset (main also wired ios-qa/daemon/test;
  ours additionally has ios-qa/scripts + browser-skills). package.json
  'test' keeps routing through the canonical strict runner.
- gbrainAvailable: main fixed the same load-flake with a strictly better
  mechanism (memoized stat-based PATH scan, no subprocess at all) —
  theirs supersedes this branch's memoized-exec probe. Main also made
  the query timeout env-overridable (GSTACK_BRAIN_TIMEOUT_MS).
- Model defaults: adopted main's lib/eval-model.ts abstraction (one
  resolution point, env-overridable per kind) and applied decision D1a
  inside it: capture defaults to Sonnet (Opus opt-in via explicit arg or
  GSTACK_EVAL_MODEL_CAPTURE); test pins updated to follow.
- Parent watchdog: main's rewrite (named parameterized tick, driven
  deterministically by its test via __testInternals__, plus handoff
  suppression semantics from session persistence) supersedes this
  branch's env-tunable interval; adopted their server + test wholesale.
- windows-free-tests: ours (curated bun run test:windows) — main's
  hand-list grew by one more file, which the curated runner subsumes
  automatically; that drift is the reason for D11.
- context-skills 0-for-26 fix: both waves made the IDENTICAL fix; kept
  this branch's comment (carries the receipts).
- .gitignore: main's superset (also ignores Package.resolved — their
  never-commit call; untracked the copy this branch had committed).

Verified: 239-test merge battery green, watchdog 8/8, eval-model 5/5,
actionlint clean, eval:select works.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gstack",
-  "version": "1.64.1.0",
+  "version": "1.65.0.0",
   "description": "Garry's Stack — Claude Code skills + fast headless browser. One repo, one install, entire AI engineering workflow.",
   "license": "MIT",
   "type": "module",