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-cat3-audit-paths/CODE_REVIEW.md

@@ -0,0 +1,12 @@
+# Code Review: fix-cat3-audit-paths
+
+## Summary
+Fix is minimal and correct. Adds a second path check for `.automaton/tasks/` prefix to handle regular projects.
+
+## Findings
+- **Correctness**: The fix correctly handles both framework mode (`tasks/...`) and regular project mode (`.automaton/tasks/...`). The `if not is_in_task_folder` guard before the second check avoids redundant evaluation.
+- **Edge cases**: Subtask paths (`.automaton/tasks/parent/subtasks/child/...`) would have `parts[2]` = `parent`, which is in `task_names` (since `_all_task_dirs` includes subtasks with their parent name). This is correct — subtask files are also excluded from unauthorized.
+- **No regressions**: Existing framework-mode audit tests still pass.
+
+## Verdict
+APPROVED — no issues found.