Fix Docker entrypoint using pinned local Prisma CLI

npx prisma was downloading Prisma CLI v7.8.0 which dropped the
url = env("DATABASE_URL") schema syntax. Use the project's own
installed Prisma CLI from node_modules instead, copied from the
builder stage.

docker-entrypoint.sh

@@ -2,7 +2,7 @@
 set -e
 
 echo "Running Prisma migrations..."
-npx prisma migrate deploy
+./node_modules/.bin/prisma migrate deploy
 
 echo "Starting Moon Base..."
 exec node server.js