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-attachments.tsx

@@ -0,0 +1,22 @@
+import Row from "@moduletrace/twui/layout/Row";
+import type { BotMessageAttachment } from "@/src/types";
+import MessageAttachment from "./message-attachment";
+
+type Props = {
+    attachments?: BotMessageAttachment[];
+};
+
+/**
+ * A message's files, right-aligned above its bubble.
+ */
+export default function MessageAttachments({ attachments }: Props) {
+    if (!attachments?.length) return null;
+
+    return (
+        <Row className="max-w-[80%] gap-2! justify-end">
+            {attachments.map((attachment) => (
+                <MessageAttachment key={attachment.id} {...attachment} />
+            ))}
+        </Row>
+    );
+}