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.json

@@ -0,0 +1,14 @@
+{
+  "gateway": {
+    "token": "a41984619a5f4b9bf9148ab6eb4abca53eb796d046cbbec5"
+  },
+  "session": {
+    "secret": "dev-session-secret-change-in-production"
+  },
+  "auth": {
+    "ldap": {
+      "bindDN": "",
+      "bindPassword": ""
+    }
+  }
+}