Replace the composer textarea with a Tiptap markdown editor

The composer now writes markdown with bold, italic, strike, code,
links, quotes and lists, from shortcuts, markdown typing or a bubble
over the selection. @ mentions a bot and # a workspace, shown as chips
and saved as [bot:ID] / [workspace:ID]. Text selected in a message can
be quoted into the composer. User messages render as markdown, and
replies tell the bot who and what the user mentioned.

Adds an ESM stand-in for use-sync-external-store, since bunext keeps
React external in page bundles and the CommonJS original requires it.

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

src/bots-queue/bot-messages-to-harness.test.ts

@@ -133,3 +133,17 @@ describe("botMessagesToHarness with files", () => {
         ).toEqual([{ role: "user", content: `[Attached earlier: "shot.png"]` }]);
     });
 });
+
+describe("botMessagesToHarness with mentions", () => {
+    test("names the bots and workspaces a user message mentions", () => {
+        expect(
+            botMessagesToHarness({
+                messages: [message("user", "ask [bot:3]"), message("bot", "[bot:3] is on it")],
+                refs: { bots: new Map([[3, { name: "Ada" }]]), workspaces: new Map() },
+            }),
+        ).toEqual([
+            { role: "user", content: "ask [bot:3]\n\n[Mentions: [bot:3] is Ada]" },
+            { role: "assistant", content: "[bot:3] is on it" },
+        ]);
+    });
+});

src/bots-queue/bot-messages-to-harness.ts

@@ -1,5 +1,6 @@
 import type { HarnessContentPart, HarnessMessage } from "@/src/harness/types";
 import type { BotMessageWithAttachments } from "@/src/types";
+import describeMessageRefs, { type MessageRefNames } from "@/src/utils/describe-message-refs";
 
 type Params = {
     messages: Pick<
@@ -11,6 +12,11 @@ type Params = {
      * messages are only named.
      */
     parts?: Map<number, HarnessContentPart[]>;
+    /**
+     * Names of the bots and workspaces the user's messages mention
+     * (`grabMessageRefNames`), told to the bot after each one.
+     */
+    refs?: MessageRefNames;
 };
 
 type Turn = { role: "user" | "assistant"; parts: HarnessContentPart[] };
@@ -22,12 +28,12 @@ type Turn = { role: "user" | "assistant"; parts: HarnessContentPart[] };
  * repeated roles. Leading bot messages are dropped so the conversation
  * starts with the user. A turn that is only text stays a string.
  */
-export default function botMessagesToHarness({ messages, parts }: Params): HarnessMessage[] {
+export default function botMessagesToHarness({ messages, parts, refs }: Params): HarnessMessage[] {
     const turns: Turn[] = [];
 
     for (const message of messages) {
         const role = message.author == "user" ? "user" : "assistant";
-        const content = messageParts({ message, role, parts });
+        const content = messageParts({ message, role, parts, refs });
 
         if (!content.length) continue;
         if (!turns.length && role == "assistant") continue;
@@ -59,12 +65,16 @@ function messageParts({
     message,
     role,
     parts,
+    refs,
 }: {
     message: Params["messages"][number];
     role: Turn["role"];
     parts?: Params["parts"];
+    refs?: Params["refs"];
 }): HarnessContentPart[] {
-    const text = replyContext({ message, text: message.text?.trim() || "" });
+    const own = message.text?.trim() || "";
+    const mentions = role == "user" && refs && own ? describeMessageRefs({ text: own, names: refs }) : "";
+    const text = replyContext({ message, text: mentions ? `${own}\n\n${mentions}` : own });
     const content: HarnessContentPart[] = text ? [{ type: "text", text }] : [];
 
     if (role == "assistant" || !message.attachments?.length) return content;

src/bots-queue/run-bot-reply.ts

@@ -17,6 +17,7 @@ import composeComputersNote from "./compose-computers-note";
 import grabSessionCarryOver from "./grab-session-carry-over";
 import jobSessionId from "@/src/functions/backend/db/bots-queue/job-session-id";
 import loadAttachmentParts from "./load-attachment-parts";
+import grabMessageRefNames from "@/src/functions/backend/db/bots/grab-message-ref-names";
 import withTakeOverRefs from "./with-take-over-refs";
 import type { BotJobContext, BotJobOutcome } from "./types";
 
@@ -124,6 +125,10 @@ export default async function runBotReply({
             messages: botMessagesToHarness({
                 messages: history,
                 parts: await loadAttachmentParts({ messages: history }),
+                refs: await grabMessageRefNames({
+                    texts: history.filter((m) => m.author == "user").map((m) => m.text || ""),
+                    user_id,
+                }),
             }),
             tools: [...tools, ...extensions.tools],
             max_steps: AppData.BotReplyMaxToolSteps,