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/utils/link-computer-refs.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, test } from "bun:test";
+import computerRef from "./computer-ref";
+import linkComputerRefs from "./link-computer-refs";
+
+describe("linkComputerRefs", () => {
+    test("links every computer a message names", () => {
+        expect(
+            linkComputerRefs({
+                text: `Your GitHub session is on ${computerRef({ id: 3 })}, not ${computerRef({ id: 12 })}.`,
+            }),
+        ).toBe("Your GitHub session is on [computer 3](#computer-3), not [computer 12](#computer-12).");
+    });
+
+    test("leaves look-alikes and existing links alone", () => {
+        const text = "See [computer:x], [link](url) and [computer:4](https://example.com)";
+
+        expect(linkComputerRefs({ text })).toBe(text);
+    });
+});