Initial commit: Backend with Bun.serve() + Drizzle ORM

- Bun 1.3.6 server setup
- MariaDB schema (projects, agents, tasks)
- Auto-migrations on startup
- WebSocket support
- Health check endpoint

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

drizzle/migrations/meta/_journal.json

@@ -0,0 +1,13 @@
+{
+  "version": "7",
+  "dialect": "mysql",
+  "entries": [
+    {
+      "idx": 0,
+      "version": "5",
+      "when": 1768858601280,
+      "tag": "0000_charming_stature",
+      "breakpoints": true
+    }
+  ]
+}