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/CODE_REVIEW.md

@@ -0,0 +1,19 @@
+# Code Review: fix-dashboard-cors-origin
+
+## Reviewed Files
+- `automaton/dashboard/ui/app.py` (`SECURITY_HEADERS`, `_send_json()`, `_send_error()`, `do_OPTIONS()`)
+- `tests/test_app.py`
+
+## Changes
+Removed wildcard CORS headers (`Access-Control-Allow-Origin: *`), replaced with security headers (`X-Content-Type-Options: nosniff`, `X-Frame-Options: DENY`).
+
+## Analysis
+- **Security**: Removing wildcard CORS eliminates the risk of cross-origin attacks from malicious local web pages
+- **Single-origin app**: The dashboard is a local web app served from a single origin — CORS is unnecessary
+- **Security headers**: `X-Content-Type-Options: nosniff` prevents MIME type sniffing, `X-Frame-Options: DENY` prevents clickjacking
+- **OPTIONS handler**: `do_OPTIONS()` still returns 204 No Content (for preflight requests) but without CORS headers
+- **Tests**: Test assertions correctly verify absence of CORS headers and presence of security headers
+
+## Verdict: PASS
+
+The fix eliminates a security vulnerability while adding useful hardening headers. Tests are properly updated.