Fix 10 audit bugs: path prefix matching, verdict parsing, CORS, stale-task detection, phase mapping

Batch 1 (High severity):
- Bug 1: --audit cat3 now checks .automaton/tasks/ paths
- Bug 4: Verdict PASS/FAIL uses structured ## Status: line parsing
- Bug 5: register-guards.sh checks .json/.jsonc, writes plugin key, strips comments
- Bug 7: --can-edit/--scope-check path prefix uses os.sep boundary

Batch 2 (Medium/Low severity):
- Bug 2: migrate-project.sh find command parentheses for -prune binding
- Bug 3: vram_detect model prefix matching with known-suffix whitelist
- Bug 6: dashboard reads .state file before artifact heuristic fallback
- Bug 8: removed wildcard CORS, added security headers (nosniff, DENY)
- Bug 9: stale-task detection uses .state.lastedit instead of .state mtime
- Bug 10: TEST_PLAN.md maps to test_design (was implement)

249 tests pass (up from 235). All 10 tasks driven through full workflow to completion.

tasks/fix-dashboard-cors-origin/DOC_REVIEW.md

@@ -0,0 +1,13 @@
+# Doc Review: fix-dashboard-cors-origin
+
+## Documentation Impact
+No external documentation changes needed. The CHANGELOG.md previously recorded "Added CORS headers" — the CHANGELOG should note their removal for this fix.
+
+## Checklist
+- [x] No new commands or flags introduced
+- [x] AGENTS.md unchanged — no CORS references in framework docs
+- [x] README.md unchanged — no CORS references
+- [x] CHANGELOG.md will be updated to note CORS removal and security headers added
+- [x] `harden-dashboard-security` task history preserved (not modified — it's a historical record)
+
+## Verdict: PASS