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/backend/db/bots-queue/notify-bot-job-failed.ts

@@ -30,7 +30,12 @@ export default async function notifyBotJobFailed({
         bot_id: job.bot_id,
         text:
             failure_message ||
-            [`I couldn't finish "${job.title || "the job"}".`, job.last_error]
+            [
+                job.kind == "reply"
+                    ? `I couldn't reply.`
+                    : `I couldn't finish "${job.title || "the job"}".`,
+                job.last_error,
+            ]
                 .filter(Boolean)
                 .join(" "),
         needs_you: true,