Rebuild the hub on Bun: Elysia API, Better Auth, Drizzle, Next.js website

The hub becomes a Bun monorepo: apps/api (Elysia, Better Auth for accounts, roles, bans, proxy device
sign-in and JWT keys; tagline linking, presence and the console as before), packages/db (Drizzle; Postgres in
production, PGlite in development and tests), and the Next.js website from apps/web. Self-hostable with
docker compose; the website deploys to Vercel-style hosts, the API to any that runs Bun or containers. The
first version, in Go, is removed.

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

turbo.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "https://turbo.build/schema.json",
+  "tasks": {
+    "build": { "dependsOn": ["^build"], "outputs": [".next/**", "!.next/cache/**", "dist/**"] },
+    "dev": { "cache": false, "persistent": true },
+    "test": { "dependsOn": ["^build"] },
+    "check-types": { "dependsOn": ["^check-types"] },
+    "lint": {}
+  }
+}