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

.prettierignore

@@ -0,0 +1,7 @@
+node_modules/
+*.sh
+scripts/
+setup.sh
+tests/*.sh
+templates/
+package-lock.json