feat: plan 16 P1 (SEC-08/09/19/20/21) — fail-open/DoS/authz hardening

- SEC-08 pii-mask: fail-closed on missing rules / broken regex (no unmasked leak)
- SEC-09: input-size cap + fail-closed reads (security-check/drift-detect/context-compress); non-UTF8 no longer crashes
- SEC-19: control-plane store POSIX flock + atomic tmp+rename write
- SEC-20: new toolchain-verify.sh (missing/PATH-shadowed/in-workspace binary -> refuse); wired into harness-preflight
- SEC-21: model-call timeout 180->60s configurable + per-run call budget
- SEC-11 realized by SEC-17 prod profile (no code)
- 5 fail-able test suites wired into ci-harness-gate.sh; test-integrity manifest regenerated

Verify: SEC+integrity gate 16/0, run-casan4 0-FAIL, adversarial 44/44, no regressions.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

AINative_OKR_CASAN5/.specify/tests/test-integrity-manifest.json

@@ -80,6 +80,14 @@
       "sha256": "71e04cba738f501e79dd6b2c02aa86c7434c5ce541af5c7e512a2c94219f1c33",
       "checks": 5
     },
+    "phase-sec08-tests.sh": {
+      "sha256": "ae4df77eed43cf235198c2489cc89a9fa083a66133137b3eb61b42fd021fd3c3",
+      "checks": 4
+    },
+    "phase-sec09-tests.sh": {
+      "sha256": "7d98d0a5a646d1500e4701710ceb4009eea22deb266c3b27b5f7b2850efc2f4a",
+      "checks": 7
+    },
     "phase-sec16-tests.sh": {
       "sha256": "3d826ca4f5c8f98837cc70846b8e2f2f83d5a598c2a5907795e8b9cc9db448c2",
       "checks": 6
@@ -88,6 +96,18 @@
       "sha256": "d68b93ebc0d16ee2369a5525fe206a9133c95ef0f931f9bfa799d21b571dbf4c",
       "checks": 6
     },
+    "phase-sec19-tests.sh": {
+      "sha256": "86d5fc377775a71920922654f96aed58952f522f4b12d1e9a290e7fa30cd6e30",
+      "checks": 4
+    },
+    "phase-sec20-tests.sh": {
+      "sha256": "86d7e8365f88631341561615923bb834823ff4548af0711ebca28353d8346e91",
+      "checks": 5
+    },
+    "phase-sec21-tests.sh": {
+      "sha256": "303503fb3670be7d1b3c2737451eff64e7f140e940d2ae16188f686af0992dfa",
+      "checks": 4
+    },
     "phase-selfimprove-tests.sh": {
       "sha256": "e91db1af16e30b18def130553f27f05691ff5540eca0593ca5e07f624c0ef938",
       "checks": 7
@@ -133,6 +153,6 @@
       "checks": 10
     }
   },
-  "total_checks": 307,
-  "suite_count": 33
+  "total_checks": 331,
+  "suite_count": 38
 }