fix: add npm-global to PATH for codex CLI, clear typing after response

- Enrich spawned process PATH with ~/.npm-global/bin so codex CLI is
  findable when running under launchd
- Clear typing indicator in streaming callback after sending response,
  instead of waiting for runner process to fully exit

src/index.ts

@@ -257,6 +257,9 @@ async function processGroupMessages(chatJid: string): Promise<boolean> {
         await channel.sendMessage(chatJid, text);
         outputSentToUser = true;
       }
+      // Clear typing indicator after sending a response — the runner may stay
+      // alive waiting for IPC messages, but the user shouldn't see "typing..."
+      await channel.setTyping?.(chatJid, false);
       // Only reset idle timer on actual results, not session-update markers (result: null)
       resetIdleTimer();
     }