fix: copy package.json and lock file to build stage in API Dockerfile

The second npm ci --omit=dev needs root package.json and lock file
to resolve workspace dependencies.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: VladUZH

apps/api/Dockerfile

@@ -14,6 +14,7 @@ WORKDIR /app
 
 COPY --from=deps /app/node_modules ./node_modules
 
+COPY package.json package-lock.json ./
 COPY packages/shared/ ./packages/shared/
 COPY apps/api/ ./apps/api/
 COPY tsconfig.base.json ./