feat(core): isolate dev and production environments

- Add IS_DEV_ENVIRONMENT flag to paths.ts for automatic detection
- Dev uses 'Gemini Nexus Dev' app data dir and '.geminiNexus-agent-dev' agent dir
- Dev proxy defaults to port 8046, production stays on 8045
- Move app.setName() before packetLogPath to ensure correct userData path
- Config, DB, logs, and ORPC packets fully isolated between dev and prod

src/server/main.ts

@@ -9,11 +9,16 @@ import { ProxyConfig } from '../types/config';
 import { setServerConfig } from './server-config';
 import { registerApiLogging } from './logging/api-logging.plugin';
 
+import { IS_DEV_ENVIRONMENT } from '../utils/paths';
+
 let app: NestFastifyApplication | null = null;
 let currentPort: number = 0;
 
+/** Default port: 8046 in development, 8045 in production */
+const DEFAULT_PORT = IS_DEV_ENVIRONMENT ? 8046 : 8045;
+
 export async function bootstrapNestServer(config: ProxyConfig): Promise<boolean> {
-  const port = config.port || 8045;
+  const port = config.port || DEFAULT_PORT;
   if (app) {
     logger.info('NestJS server already running.');
     return true;