chore: add 17 operational rules and rule index

- Create .claude/rules/ with all 17 standard rule files (01-security through 17-document-imports)
- Add Operational Rules section with Rule Index to .claude/CLAUDE.md

.claude/rules/03-environment-safety.md

@@ -0,0 +1,26 @@
+# Environment and Data Safety (PARAMOUNT)
+
+Verify the target before every operation affecting external systems.
+
+## Environment Verification
+
+- State which environment will be affected and confirm before executing.
+- Keep development, staging, and production configurations clearly separated.
+- Copy production data to development only with explicit approval.
+
+## Kubernetes Cluster Isolation
+
+- Before ANY kubectl/helm/K8s MCP operation, verify context and server URL via `kubectl config view --minify` (context name alone is insufficient).
+- If context does not match this project's cluster, STOP and alert the user.
+- Specify namespace explicitly. Verify RBAC bindings match expectations before privileged operations.
+
+## Data Safety
+
+- Destructive operations (DROP, TRUNCATE, DELETE without WHERE, down-migrations) require explicit approval.
+- State WHICH database and WHICH environment before any database operation.
+- Back up data before migrations in non-development environments.
+
+## Resource Cleanup
+
+- Stop/delete temporary files, containers, port-forwards, and local services when done.
+- Before ending a session, verify no orphaned processes remain.