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/computer-ref.ts

@@ -0,0 +1,7 @@
+/**
+ * How a bot names one of its computers in a message: `[computer:3]`. The
+ * chat shows it as a button that switches the bot to that computer.
+ */
+export default function computerRef({ id }: { id: number | string }) {
+    return `[computer:${id}]`;
+}

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);
+    });
+});

src/utils/link-computer-refs.ts

@@ -0,0 +1,18 @@
+/**
+ * The link target a computer ref (`computerRef`) becomes, e.g.
+ * `#computer-3`. The chat's markdown renders these links as buttons that
+ * switch the bot to that computer.
+ */
+export const ComputerRefHrefPrefix = "#computer-";
+
+/**
+ * Turns every computer ref in a message into a markdown link to
+ * `#computer-<id>`, so it survives markdown rendering as a link the chat
+ * can swap for a switch button.
+ */
+export default function linkComputerRefs({ text }: { text: string }) {
+    return text.replace(
+        /\[computer:(\d+)\](?!\()/g,
+        (_, id: string) => `[computer ${id}](${ComputerRefHrefPrefix}${id})`,
+    );
+}

src/utils/message-preview.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, test } from "bun:test";
+import messagePreview from "./message-preview";
+
+describe("messagePreview", () => {
+    test("strips markdown and names computers plainly", () => {
+        expect(
+            messagePreview({
+                text: "## Found it\n\nYour **GitHub** session is on [computer:3]. See [the docs](https://x.y) and `search_computers`.\n\n- *one*\n- two",
+            }),
+        ).toBe("Found it Your GitHub session is on a computer. See the docs and search_computers. one two");
+    });
+
+    test("keeps code text without its fences", () => {
+        expect(messagePreview({ text: "Run:\n```bash\nls ~\n```" })).toBe("Run: ls ~");
+    });
+
+    test("leaves plain text alone", () => {
+        expect(messagePreview({ text: "All done, 3 files_moved." })).toBe("All done, 3 files_moved.");
+    });
+});

src/utils/message-preview.ts

@@ -0,0 +1,17 @@
+/**
+ * A bot message as one line of plain text, for the rail's preview: no
+ * markdown syntax, links as their text, computer refs (`computerRef`) as
+ * "a computer", whitespace collapsed.
+ */
+export default function messagePreview({ text }: { text: string }) {
+    return text
+        .replace(/```[^\n]*\n?/g, "")
+        .replace(/\[computer:\d+\](?!\()/g, "a computer")
+        .replace(/!?\[([^\]]*)\]\([^)]*\)/g, "$1")
+        .replace(/^\s{0,3}(#{1,6}\s+|>\s?|[-*+]\s+|\d+\.\s+)/gm, "")
+        .replace(/(\*\*|__|~~|`)/g, "")
+        .replace(/(^|\s)[*_](\S[^*_]*\S|\S)[*_](?=\s|$|[.,;:!?])/g, "$1$2")
+        .replace(/\|/g, " ")
+        .replace(/\s+/g, " ")
+        .trim();
+}