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/production.json

@@ -0,0 +1,11 @@
+{
+  "server": {
+    "port": 3000
+  },
+  "session": {
+    "secret": "CHANGE-ME-NOW"
+  },
+  "auth": {
+    "disabled": false
+  }
+}