Add the harness, envs, per-bot models and chat attachments

- Harness: providers, model catalog synced hourly, automatic free picks,
  cooldowns, tool loop with context trimming, MCP computer tools
- Bots queue runs replies and tasks through the harness; jobs wait
  (attempt refunded) while every model is resting
- Envs: Settings > Environment, scoped general/workspace/computer,
  written to computers and redacted from tool output
- Models: Settings > Models, per-harness provider select defaulting to
  OpenRouter, and a models modal on each bot's chat (the coordinator's
  edits the defaults)
- Chat: thinking row while a reply runs, file attachments (upload,
  paste, drop) that replies read as images, audio and document text
- Fix media uploads failing after a user's first file, and private
  files being served from the public media path

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

src/pages/admin/bots/[bot_id]/(partials)/message-thread.tsx

@@ -1,17 +1,18 @@
 import Stack from "@moduletrace/twui/layout/Stack";
-import type { BUN_SQLITE_COBBLE_BOT_MESSAGES } from "@/db/types/db";
-import type { BotWithLastMessage } from "@/src/types";
+import type { BotMessageWithAttachments, BotWithLastMessage } from "@/src/types";
 import groupMessages from "../(utils)/group-messages";
+import BotThinkingRow from "./bot-thinking-row";
 import MessageGroupBlock from "./message-group-block";
 
 type Props = {
     bot: BotWithLastMessage;
-    messages: BUN_SQLITE_COBBLE_BOT_MESSAGES[];
+    messages: BotMessageWithAttachments[];
 };
 
 /**
  * Bottom-anchored: the stack sits 24px above the composer rule and grows
  * upward. Empty space belongs at the top. New messages announce politely.
+ * While the bot works on a reply, a thinking row sits under the last one.
  */
 export default function MessageThread({ bot, messages }: Props) {
     const groups = groupMessages({ messages });
@@ -27,6 +28,7 @@ export default function MessageThread({ bot, messages }: Props) {
                 {groups.map((group) => (
                     <MessageGroupBlock key={group.key} bot={bot} group={group} />
                 ))}
+                <BotThinkingRow bot={bot} />
             </Stack>
         </Stack>
     );