policies: add standard policy files, formatting, and secret scanning

- Add .editorconfig, .prettierrc, .prettierignore, .gitignore
- Add Makefile with fmt, fmt-check, secret-scan, test (skip) targets
- Add package.json with prettier
- Add tools/secret-scan.sh
- Add .secret-scan-allowlist for documentation token format references
- Sanitize documentation to use generic placeholders
- Auto-format with prettier
- make check passes clean

configs/openclaw-anthropic.json

@@ -4,9 +4,7 @@
 
   "agents_defaults_model": {
     "primary": "anthropic/claude-opus-4-6",
-    "fallbacks_to_add": [
-      "anthropic/claude-sonnet-4-6"
-    ]
+    "fallbacks_to_add": ["anthropic/claude-sonnet-4-6"]
   },
 
   "agents_defaults_models": {