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-migrate-find-precedence/IMPLEMENTATION.md

@@ -0,0 +1,20 @@
+# Implementation: fix-migrate-find-precedence
+
+## Bug
+`migrate-project.sh` uses `find` without parentheses around `-name` tests combined with `-prune`, causing `-prune` to bind only to the last `-name` test. This results in incorrect pruning — some directories that should be pruned are still traversed.
+
+## Fix
+Added parentheses around the `-name` tests in the `find` command at `scripts/migrate-project.sh:108`:
+
+```diff
+- find . -name .git -o -name node_modules -o -name .automaton -prune ...
++ find . \( -name .git -o -name node_modules -o -name .automaton \) -prune ...
+```
+
+This ensures `-prune` applies to the entire OR-group, not just the last `-name` test.
+
+## Files Changed
+- `scripts/migrate-project.sh` (line 108): added `\(` and `\)` around the `-name` group
+
+## Tests
+No new tests added — shell script syntax change only. Verified with `bash -n scripts/migrate-project.sh`.