fix(ci): small-lane batch — timeouts, right-sizing, windows cache warm-start

- timeout-minutes on the 6 remaining unbounded jobs (actionlint 5,
  skill-docs 10, version-gate 10, make-pdf-gate 15, pr-title-sync 5,
  evals build-image 15) — a hung step sat on GitHub's 360-min default
- right-size measured-over-long timeouts: dependency-review 10→5,
  windows-setup-e2e 15→10
- dependency-review: 2-core runner (28s API call on an 8-core box) and
  drop .github/workflows/** from its trigger paths (workflow edits have
  no dependencies to review)
- windows caches gain restore-keys: a lockfile bump paid the 26s/43s
  restore for a guaranteed cold miss

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

.github/workflows/version-gate.yml

@@ -15,6 +15,7 @@ jobs:
   check:
     name: Check VERSION is not stale vs queue
     runs-on: ubicloud-standard-2
+    timeout-minutes: 10
     permissions:
       contents: read
       pull-requests: read