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/functions/server/media/handle-media-server.ts

@@ -59,6 +59,14 @@ export default async function handleMediaServer({
         });
 
         media = media_res.singleRes || undefined;
+
+        /**
+         * A private file is only served through `/media/private`, to its
+         * owner.
+         */
+        if (media?.is_private) {
+            media = undefined;
+        }
     }
 
     if (!media?.id) {