fix: dedicated migrator stage for payload migrate

Build stage runs pnpm build which changes ESM resolution context.
New migrator stage has deps+src only — clean env for tsx/payload migrate.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -18,6 +18,12 @@ ENV WATCHPACK_POLLING=true
 EXPOSE 3000
 CMD ["pnpm", "dev"]
 
+# --- Migrator (deps + src only, no Next.js build — used for pnpm payload migrate) ---
+FROM base AS migrator
+COPY --from=deps /app/node_modules ./node_modules
+COPY . .
+CMD ["pnpm", "payload", "migrate"]
+
 # --- Build ---
 FROM base AS build
 COPY --from=deps /app/node_modules ./node_modules

docker-compose.prod.yml

@@ -15,7 +15,7 @@ services:
   migrator:
     build:
       context: .
-      target: build
+      target: migrator
     command: pnpm payload migrate
     env_file:
       - .env.production