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-vram-model-prefix-match/SPEC.md

@@ -0,0 +1,15 @@
+# Spec: fix-vram-model-prefix-match
+
+## Problem
+`scripts/vram_detect.py:396` uses `model_name.lower().startswith(key.lower())` to match model names. This prefix matching causes false matches: `phi-4-mini` matches `phi-4` (16000), and unknown models starting with known prefixes get incorrect context windows instead of the fallback.
+
+## Fix
+Try exact match first, then longest-prefix match (sort keys by length descending). Only match if the model name equals the key or starts with `key + "-"` (to avoid `phi-4` matching `phi-40`).
+
+## Acceptance Criteria
+- `phi-4-mini-instruct` does NOT match `phi-4` — returns fallback (128000)
+- `gpt-4o` still matches `gpt-4o` (exact) — returns 128000
+- `gpt-4o-mini` matches `gpt-4o-mini` (exact) — returns 128000
+- `claude-3-5-sonnet-20241022` matches exact entry — returns 200000
+- Existing tests in `test_vram_detect.py` still pass
+- Add test for the prefix edge case