refactor: extract dashboard and message-runtime from index.ts

- Extract dashboard code into src/dashboard.ts
- Extract message runtime into src/message-runtime.ts
- Improve group-queue with better concurrency handling
- Update agent-runner with enhanced env/config passing
- Simplify DB operations and cleanup unused code
- Update README for Codex SDK architecture

src/router.ts

@@ -34,16 +34,6 @@ export function formatOutbound(rawText: string): string {
   return text;
 }
 
-export function routeOutbound(
-  channels: Channel[],
-  jid: string,
-  text: string,
-): Promise<void> {
-  const channel = channels.find((c) => c.ownsJid(jid) && c.isConnected());
-  if (!channel) throw new Error(`No channel for JID: ${jid}`);
-  return channel.sendMessage(jid, text);
-}
-
 export function findChannel(
   channels: Channel[],
   jid: string,