feat: add production deployment config

- Add docker-compose.prod.yml and Caddyfile for Caddy reverse proxy
- Add production stages to frontend Dockerfile (nginx for static files)
- Fix monorepo package exports for production builds (dist/src paths)
- Add CORS_ORIGIN env var for cross-origin config
- Add Better Auth baseURL, cookie domain, and trusted origins from env
- Use VITE_API_URL for API calls in auth-client and play route
- Add credentials: include for cross-origin fetch requests
- Remove unused users table from schema

packages/db/src/db/schema.ts

@@ -100,20 +100,6 @@ export const translations = pgTable(
   ],
 );
 
-export const users = pgTable("users", {
-  id: uuid().primaryKey().defaultRandom(),
-  openauth_sub: text().unique().notNull(),
-  email: varchar({ length: 255 }).unique(),
-  display_name: varchar({ length: 100 }).unique(),
-  created_at: timestamp({ withTimezone: true }).defaultNow().notNull(),
-  last_login_at: timestamp({ withTimezone: true }),
-});
-// KNOWN LIMITATION: email is nullable (GitHub users may have no public email)
-// and unique, but two OAuth providers can return the same email for different
-// accounts. For MVP this is acceptable since users are identified by
-// openauth_sub, not email. If multi-provider login per user is added later,
-// consider a separate user_emails table.
-
 export const decks = pgTable(
   "decks",
   {