fase(23): observability and health probes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main.ts

@@ -93,6 +93,9 @@ import { createServer } from './api/server';
 import { SocketGateway } from './realtime/SocketGateway';
 
 async function bootstrap(): Promise<void> {
+  // Startup probe — measure total boot time
+  const startupAt = Date.now();
+
   // 1. Config
   const config = loadConfig();
 
@@ -247,7 +250,8 @@ async function bootstrap(): Promise<void> {
   await new Promise<void>((resolve) => {
     httpServer.listen(config.port, config.host, resolve);
   });
-  logger.info({ port: config.port, host: config.host }, 'ABE server ready');
+  const startupMs = Date.now() - startupAt;
+  logger.info({ port: config.port, host: config.host, startupMs }, 'ABE server ready');
 
   // 14. Graceful shutdown
   let shuttingDown = false;