feat: plan 16-01

AINative_OKR_CASAN5/.specify/scripts/bash/security-check.sh

@@ -253,8 +253,14 @@ if [[ "$MODE" == "input" ]]; then
   #     silent skip. Off by default so CI without a model stays non-strict.
   #   * CASAN_SEMANTIC_CLASSIFY=1 (non-strict) — best-effort. On model outage we
   #     keep the regex verdict but log SEMANTIC_SKIPPED loudly (no silent pass).
+  # SEC-17 (ARCH-03): strict is ON when explicitly set, OR unset under prod profile
+  # (secure-by-default). An explicit CASAN_SECURITY_STRICT=0 (internal scans) wins.
+  STRICT_ON=0
+  if [[ "${CASAN_SECURITY_STRICT:-0}" == "1" || ( -z "${CASAN_SECURITY_STRICT+x}" && "${CASAN_PROFILE:-}" == "prod" ) ]]; then
+    STRICT_ON=1
+  fi
   SEMANTIC_REQUIRED=0
-  if [[ "${CASAN_SECURITY_STRICT:-0}" == "1" || "${CASAN_SEMANTIC_CLASSIFY:-0}" == "1" ]]; then
+  if [[ "$STRICT_ON" == "1" || "${CASAN_SEMANTIC_CLASSIFY:-0}" == "1" ]]; then
     SEMANTIC_REQUIRED=1
   fi
   if [[ "$STATUS" != "blocked" && "$SEMANTIC_REQUIRED" == "1" ]]; then
@@ -271,7 +277,7 @@ if [[ "$MODE" == "input" ]]; then
       MATCHED_RULES+=("semantic-injection")
     elif [[ -z "$SEM_VERDICT" ]]; then
       # Model unreachable / no usable verdict.
-      if [[ "${CASAN_SECURITY_STRICT:-0}" == "1" ]]; then
+      if [[ "$STRICT_ON" == "1" ]]; then
         STATUS="blocked"; ACTION="block"; RISK_LEVEL="high"
         MATCHED_RULES+=("semantic-strict-unavailable")
         casan_log error security "SEMANTIC_STRICT_FAIL_CLOSED trace_id=$TRACE_ID reason=model_unavailable action=block"