fix(docker): add NEXT_PUBLIC_API_BASE_URL to frontend containers

When running in Docker, the frontend needs to use 'http://backend:8000'
as the backend URL for Next.js rewrites. This env var is set to use
the Docker service name for proper container-to-container communication.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.deploy.yml

@@ -288,6 +288,7 @@ services:
     environment:
       - NODE_ENV=production
       - NEXT_PUBLIC_API_URL=${NEXT_PUBLIC_API_URL}
+      - NEXT_PUBLIC_API_BASE_URL=http://backend:8000
     depends_on:
       backend:
         condition: service_healthy

docker-compose.dev.yml

@@ -249,6 +249,7 @@ services:
     environment:
       - NODE_ENV=development
       - NEXT_PUBLIC_API_URL=${NEXT_PUBLIC_API_URL}
+      - NEXT_PUBLIC_API_BASE_URL=http://backend:8000
     depends_on:
       backend:
         condition: service_healthy