fix: pass Vite env vars as Docker build args

Vite reads env vars at build time, not runtime. The previous setup
only set them in docker-compose 'environment' which is only available
at container runtime. Now they are passed as build args so Vite can
embed the correct API URL during the build process.

- Add build args to web service in both compose files
- Update Dockerfile to accept ARGs and set ENV for Vite
- Fixes login redirect always going to localhost:8000

docker-compose.yml

@@ -71,6 +71,8 @@ services:
     build:
       context: ./apps/web
       dockerfile: Dockerfile
+      args:
+        VITE_API_BASE_URL: http://localhost:8000
     container_name: hq-web
     environment:
       VITE_API_BASE_URL: http://localhost:8000