Add workspaces, computers, bot memory and the bots queue

- Schema: workspaces (+ workspace_bots, workspace_computers), containers,
  computers, bot_computers, bots.memory, workspaces.system_prompt, and
  bots_queue as a bun-sqlite isQueue table
- Main computer (and its container record) ensured with the coordinator on
  signup, seed and /admin/bots; the coordinator's access to it is locked
- Effective computer access: direct grants plus workspace computers
- Full bot prompt: core instructions, workspace prompts, then memory;
  bots can rewrite their memory and system prompt
- Queue helpers on the native BunSQLite.queue API, plus a handler that
  heartbeats, serializes per computer, recovers after restarts, reports
  lost jobs, supports cancelling and pushes outcomes over the WebSocket
- Enable SQLite foreign keys at startup so schema cascades fire
- Prune finished jobs daily

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

src/cron/index.ts

@@ -1,5 +1,6 @@
 import bunext from "@moduletrace/bunext";
 import cronHeartbeat from "./heartbeat";
+import pruneBotsQueue from "./prune-bots-queue";
 import registerCronJob from "./register-cron-job";
 
 export default function cron() {
@@ -15,4 +16,10 @@ export default function cron() {
         task: cronHeartbeat,
         run_on_start: true,
     });
+
+    registerCronJob({
+        title: "prune-bots-queue",
+        schedule: "@daily",
+        task: pruneBotsQueue,
+    });
 }