Add computer switching, crew reporting, job steps and markdown chat

- Bots have a current computer (bots.computer_id), switched from the chat
  header beside the model button or by clicking a computer the bot names
  ([computer:ID]); tasks run on it by default
- search_computers runs one read-only command on all of a bot's computers;
  chat replies know their computers (compose-computers-note)
- The coordinator can use every computer and grants or revokes crew access
  with assign_computer
- Delegated jobs record requested_by_bot_id; the worker's result or failure
  is reported back in the coordinator's conversation
- bots_queue_updates records each model turn of a job, pushed live and shown
  in the working-on panel
- Live relay: every process pushes new messages, job steps and bot changes
  from the database to its own sockets, so work done elsewhere shows live
- Bot messages render as markdown (react-markdown + remark-gfm, no raw HTML)
  with twui components; rail previews are plain text
- Fix header button overflow in the model and computer selects
- Bump @moduletrace/twui to 0.1.2

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

src/harness/tools/bot/start-task-tool.ts

@@ -7,7 +7,7 @@ type Params = {
     user_id: number | string;
     bot_id: number | string;
     /**
-     * The bot's computers, its main one first (`grabBotComputers`).
+     * The bot's computers, the current one first (`grabBotComputers`).
      */
     computers: BUN_SQLITE_COBBLE_COMPUTERS[];
     /**
@@ -40,7 +40,7 @@ export default function startTaskTool({
         name: "start_task",
         description: `Queue work that takes a while or needs a computer. It runs in the background and its result is posted in this chat. Write the instructions as a full brief for yourself: what to do, where, and how you'll know it's done. ${
             computers.length
-                ? `Computers you can use: ${listed}. Defaults to ${computers[0]!.id}.`
+                ? `Computers you can use: ${listed}. Defaults to ${computers[0]!.id}, the one you're on.`
                 : `You have no computer, so the task can't run commands or browse.`
         }`,
         schema: z.object({