Refactor: Use @simpleworkjs/conf for configuration

- Replace ENV vars with proper config system
- Add conf/ directory with base, development, production, secrets
- Add secrets.example.js template
- Update .gitignore for secrets.js
- Show environment in startup banner

conf/development.js

@@ -0,0 +1,16 @@
+/**
+ * Development environment configuration
+ */
+
+module.exports = {
+  auth: {
+    disabled: true, // Skip auth in dev
+    ldap: {
+      enabled: false
+    }
+  },
+  
+  server: {
+    // Vite runs on 5173, proxy from there
+  }
+};