Implement guardrail hooks for dangerous operation prevention

- Add PreToolUse hook intercepting Bash, Write, Edit
- Block catastrophic commands (rm -rf /, mkfs, etc.)
- Require confirmation for operations outside safe paths
- Git-aware: operations in git repos are allowed
- Session allowlist for user-confirmed operations
- Audit logging to logs/guardrail.jsonl
- Clear session allowlist on SessionEnd

Config: state/guardrails.json
Scripts: hooks/scripts/guardrail.py, guardrail-confirm.py

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

hooks/hooks.json

@@ -41,6 +41,18 @@
           }
         ]
       }
+    ],
+    "PreToolUse": [
+      {
+        "matcher": "Bash|Write|Edit",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "~/.claude/hooks/scripts/guardrail.py",
+            "timeout": 5
+          }
+        ]
+      }
     ]
   }
 }