Add initial Prisma migration

README.md

@@ -23,7 +23,7 @@ WatchLink is a self-hosted shared-watch web app with persistent user rooms, loca
 ```bash
 npm install
 cp .env.example .env
-npm run db:push
+npm run db:migrate
 npm run dev
 ```
 
@@ -108,6 +108,8 @@ docker compose up --build
 
 The Compose stack exposes the web app on `http://localhost:${HOST_PORT:-3000}` and uses a Postgres volume named `watchlink_postgres-data`. Keep the container `PORT` at `3000`; change `HOST_PORT` when another container already uses port 3000 on the host.
 
+On first start, the web container runs `prisma migrate deploy` before starting Next.js. This creates the required tables in a clean Postgres volume.
+
 Build and publish the Gitea image:
 
 ```bash