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)/composer-attach-button.tsx

@@ -1,17 +1,30 @@
 import Button from "@moduletrace/twui/layout/Button";
 import { Plus } from "lucide-react";
+import { AppData } from "@/src/data/app-data";
+import pickFiles from "../(utils)/pick-files";
+
+type Props = {
+    disabled?: boolean;
+    onFiles: (params: { files: File[] }) => void;
+};
 
 /**
- * Attachments are not designed yet; the control is present but inert.
+ * Opens the file picker for the next message's attachments.
  */
-export default function ComposerAttachButton() {
+export default function ComposerAttachButton({ disabled, onFiles }: Props) {
     return (
         <Button
-            title="Attachments are not available yet"
+            title={
+                disabled
+                    ? `Up to ${AppData.BotAttachmentMaxFiles} files per message`
+                    : "Attach files"
+            }
+            type="button"
             variant="ghost"
             color="text"
-            aria-disabled="true"
-            className="shrink-0 p-1! -m-1 text-ink dark:text-ink cursor-not-allowed rounded-default-xs focus-visible:ring-2 focus-visible:ring-ink"
+            disabled={disabled}
+            onClick={() => pickFiles({ onFiles })}
+            className="shrink-0 p-1! -m-1 text-ink dark:text-ink rounded-default-xs focus-visible:ring-2 focus-visible:ring-ink"
         >
             <Plus size={16} aria-hidden />
         </Button>