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-can-edit-path-prefix/IMPLEMENTATION.md

@@ -0,0 +1,12 @@
+# Implementation: fix-can-edit-path-prefix
+
+## Changes
+- **scripts/status.py** `cmd_can_edit()` (5 locations): Replaced `str(file_path).startswith(proj_str)` with `str(file_path).startswith(proj_str + os.sep) or str(file_path) == proj_str` to prevent sibling-directory bypass. Same fix applied to `auto_str` (framework directory) checks.
+  - Line ~986: `--can-edit --project --file` scope check
+  - Line ~1039: `--can-edit --task --file` framework case
+  - Line ~1045: `--can-edit --task --file` regular project case
+  - Line ~1082: `--scope-check` project check
+  - Line ~1087: `--scope-check` framework check
+
+## Test
+- `tests/test_status.py::TestCanEditPathPrefix` — 3 tests: sibling directory rejected by scope-check, subdirectory accepted by scope-check, sibling directory rejected by can-edit --task --file.