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/ADVERSARIAL_BUG_REPORT.md

@@ -0,0 +1,13 @@
+# Adversarial Bug Report: fix-vram-model-prefix-match
+
+## Attack Vectors Tested
+1. **Empty model name**: Returns 0 (no match) — correct
+2. **Model name with only separator**: `:` or `-` alone — no match, correct
+3. **Case sensitivity**: `key.lower()` and `name_lower` handle case-insensitive matching correctly
+4. **Suffix that partially matches known suffix**: `instruct` vs `instructional` — `instructional` would not match since `split("-")[0]` gives `instructional` which is not in the set
+5. **Multiple separators**: `deepseek-r1:7b-instruct` — matches via `:` before reaching `-` check (correct, Ollama tag takes priority)
+
+## Findings
+No bugs found.
+
+## Verdict: PASS