Enhance policy system tests and documentation.

Added extensive tests for default-permissive access control, read/write follow whitelists, and privileged-only fields. Updated policy documentation with new configuration examples, access control reference, and logging details.

.claude/settings.local.json

@@ -174,7 +174,9 @@
       "Bash(GOOS=js GOARCH=wasm go build:*)",
       "Bash(go mod graph:*)",
       "Bash(xxd:*)",
-      "Bash(CGO_ENABLED=0 go mod tidy:*)"
+      "Bash(CGO_ENABLED=0 go mod tidy:*)",
+      "WebFetch(domain:git.mleku.dev)",
+      "Bash(CGO_ENABLED=0 LOG_LEVEL=trace go test:*)"
     ],
     "deny": [],
     "ask": []