Let a bot answer its sessions side by side, and show a due reply in each

Replies were locked per bot, so a long reply in one session held up every
other session's reply with nothing shown. The lock is now per session. A
chat shows the thinking row whenever the user has the last word, rather
than from the bot's face (one per user, shared by every session), so it
shows even while the bot works elsewhere. A task waiting for its busy
computer says so, and a job finishing while another still runs puts back
the running one's face.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/dict/bot-queue-dict.ts

@@ -55,6 +55,12 @@ export const BotNeedsYouStatusLine = "Waiting on you";
  */
 export const BotWaitingStatusLine = "Waiting for a free model";
 
+/**
+ * The bot's status line while its task waits for another job on the same
+ * computer to finish.
+ */
+export const BotComputerBusyStatusLine = "Waiting for its computer";
+
 /**
  * How a job step that called a tool reads in the chat's working row, by
  * tool name. Tools not listed read "Using <name>".