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]>

package.json

@@ -38,7 +38,7 @@
         "@modelcontextprotocol/sdk": "^1.32.1",
         "@moduletrace/bun-sqlite": "^1.3.0",
         "@moduletrace/bunext": "^1.3.3",
-        "@moduletrace/twui": "^0.1.1",
+        "@moduletrace/twui": "^0.1.2",
         "ace-builds": "^1.44.0",
         "dayjs": "^1.11.23",
         "gray-matter": "^4.0.3",