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/bots-queue/parse-job-json.ts

@@ -0,0 +1,22 @@
+type Params = {
+    text?: string | null;
+};
+
+/**
+ * Reads a job's `params` or `checkpoint` column. Null when empty or not a
+ * JSON object.
+ */
+export default function parseJobJson({
+    text,
+}: Params): Record<string, unknown> | null {
+    if (!text) return null;
+
+    try {
+        const value = JSON.parse(text);
+        return value && typeof value == "object" && !Array.isArray(value)
+            ? value
+            : null;
+    } catch {
+        return null;
+    }
+}