Fix: Use JSON config files for ESM compatibility

- Replace @simpleworkjs/conf with simple custom loader
- Use JSON config files (base, development, production, secrets)
- Add config.js with ESM-compatible deep merge
- Support env var overrides for critical settings
- Auth disabled in dev mode via development.json

conf/secrets.example.json

@@ -0,0 +1,14 @@
+{
+  "gateway": {
+    "token": "your-gateway-token-here"
+  },
+  "session": {
+    "secret": "generate-a-random-string-here"
+  },
+  "auth": {
+    "ldap": {
+      "bindDN": "cn=admin,dc=example,dc=com",
+      "bindPassword": "ldap-admin-password"
+    }
+  }
+}