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/secrets.example.js

@@ -0,0 +1,26 @@
+/**
+ * Example secrets file
+ * 
+ * Copy this to secrets.js and fill in your actual values
+ * secrets.js is ignored by git
+ */
+
+module.exports = {
+  gateway: {
+    // Your OpenClaw gateway token
+    token: 'your-gateway-token-here'
+  },
+  
+  session: {
+    // Random string for session signing
+    secret: 'generate-a-random-string-here'
+  },
+  
+  auth: {
+    ldap: {
+      // LDAP bind credentials (if needed for search)
+      bindDN: 'cn=admin,dc=example,dc=com',
+      bindPassword: 'ldap-admin-password'
+    }
+  }
+};