Trim page props and page the conversation's messages

Bot and workspace lists in page props leave out instructions, memory and
workspace context, and carry the last message as a short preview. The
header avatar's edit form loads the bot's instructions when it opens.
The conversation renders its latest 30 messages and loads older ones as
the thread scrolls to its top.

Also: the composer shows a placeholder until its editor loads, and
`bun start` no longer builds first.

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

src/pages/admin/bots/[bot_id]/(sections)/conversation.tsx

@@ -22,6 +22,7 @@ import useTaskProgress from "../(hooks)/use-task-progress";
 import useReplyProgress from "../(hooks)/use-reply-progress";
 import useReplyCatchUp from "../(hooks)/use-reply-catch-up";
 import useSpeakMessage from "../(hooks)/use-speak-message";
+import useOlderMessages from "../(hooks)/use-older-messages";
 import ConversationHeader from "../(partials)/conversation-header";
 import MessageThread from "../(partials)/message-thread";
 import Composer, { type ComposerHandle } from "../(partials)/composer";
@@ -35,7 +36,8 @@ import ComputerViewerModal from "../(partials)/computer-viewer-modal";
  * buttons in the thread, so a switch from either shows in both; either
  * can open one in the viewer. Bot messages can be read aloud, one at a
  * time. Text selected in the thread can be quoted in the composer, which
- * mentions the crew and workspaces the user sees.
+ * mentions the crew and workspaces the user sees. The page brings the
+ * session's latest messages; older ones load as the thread scrolls up.
  */
 export default function Conversation() {
     const { pageProps } = useContext(AppContext);
@@ -99,6 +101,19 @@ export default function Conversation() {
         task: pageProps?.bot_task || null,
     });
 
+    const older = useOlderMessages({
+        session_id,
+        has_more: Boolean(pageProps?.bot_messages_more),
+        first_message_id: Number(messages[0]?.id) || null,
+        onLoaded: ({ messages: older_messages }) =>
+            setMessages((prev) => [
+                ...older_messages.filter(
+                    (message) => !prev.some((m) => m.id == message.id),
+                ),
+                ...prev,
+            ]),
+    });
+
     const thread_messages = useMemo(
         () => [...messages, ...pending_messages],
         [messages, pending_messages],
@@ -239,6 +254,7 @@ export default function Conversation() {
                                     reply_progress={reply_progress}
                                     receiving={pending_messages.length > 0}
                                     has_task={Boolean(progress.task_id)}
+                                    older={older}
                                     onQuote={({ text }) =>
                                         composer.current?.insertQuote({ text })
                                     }