policies: add standard policy files, linting, formatting

- Add .editorconfig, .eslintrc.json, .prettierrc, .prettierignore, .dockerignore, .gitignore
- Add Makefile with lint, fmt, fmt-check, secret-scan, test (skip) targets
- Add package.json with eslint@^8.56.0, eslint-plugin-security, prettier
- Add tools/secret-scan.sh
- Fix unused variable (fs -> _fs)
- Auto-format with prettier
- make check passes clean (0 errors, 11 warnings)

Makefile

@@ -0,0 +1,23 @@
+export NODE_ENV := development
+
+.PHONY: check install test lint fmt fmt-check secret-scan
+
+check: install lint fmt-check secret-scan test
+
+install:
+	npm install
+
+test:
+	@echo "[SKIP] No tests found"
+
+lint:
+	npx eslint .
+
+fmt:
+	npx prettier --write .
+
+fmt-check:
+	npx prettier --check .
+
+secret-scan:
+	bash tools/secret-scan.sh .