Fix orchestrator process hang after cleanup

The orchestrator process was hanging after completing its work because:
1. Fire-and-forget Redis operations in MessageBus.handleMessage() left
   unhandled promises that kept the event loop alive
2. No explicit process.exit() call after cleanup

Changes:
- coordination.ts: Add .catch(() => {}) to fire-and-forget Redis ops
- orchestrator.ts: Add explicit process.exit(exitCode) after cleanup
- orchestrator.ts: Improve error handling in main() with proper exit codes

Tested: Pipeline mksup1wq completed full flow and exited cleanly.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

agents/multi-agent/orchestrator.ts

@@ -389,6 +389,7 @@ The solution should consider fault tolerance, data consistency, and cost optimiz
 
   const orchestrator = new MultiAgentOrchestrator(model);
 
+  let exitCode = 0;
   try {
     await orchestrator.initialize();
     const metrics = await orchestrator.runTask(task);
@@ -402,9 +403,15 @@ The solution should consider fault tolerance, data consistency, and cost optimiz
 
   } catch (e: any) {
     console.error("Orchestrator error:", e.message);
+    exitCode = 1;
   } finally {
     await orchestrator.cleanup();
+    // Explicitly exit to ensure all connections are closed
+    process.exit(exitCode);
   }
 }
 
-main().catch(console.error);
+main().catch((e) => {
+  console.error("Fatal error:", e);
+  process.exit(1);
+});