Fix nginx deploy: use SCP to copy config files

The production server doesn't have a git repo, so we can't use git
commands to update files. Instead, use appleboy/scp-action to copy
nginx.conf and docker-compose.prod.yml from the runner to the server,
then restart nginx.

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

.github/workflows/auth_build.yml

@@ -122,6 +122,16 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Copy config files to server
+        uses: appleboy/scp-action@v0.1.7
+        with:
+          host: ${{ secrets.DO_DROPLET_IP }}
+          username: deploy
+          key: ${{ secrets.DO_SSH_KEY }}
+          source: "nginx/nginx.conf,docker-compose.prod.yml"
+          target: "/opt/eagle0"
+          strip_components: 0
+
       - name: Deploy auth service to production
         uses: appleboy/ssh-action@v1.0.3
         with:
@@ -199,17 +209,10 @@ jobs:
             # Show container status
             docker compose -f docker-compose.prod.yml ps auth
 
-            # Update nginx config and restart only if changed
-            echo "=== Checking for nginx config changes ==="
-            git fetch origin main
-            if ! git diff --quiet HEAD origin/main -- nginx/nginx.conf docker-compose.prod.yml; then
-              echo "Config files changed, updating and restarting nginx..."
-              git checkout origin/main -- nginx/nginx.conf docker-compose.prod.yml
-              docker compose -f docker-compose.prod.yml up -d --no-deps --force-recreate nginx
-              echo "Nginx restarted with updated config"
-            else
-              echo "No nginx config changes, skipping restart"
-            fi
+            # Restart nginx with updated config (copied via SCP step)
+            echo "=== Restarting nginx ==="
+            docker compose -f docker-compose.prod.yml up -d --no-deps --force-recreate nginx
+            echo "Nginx restarted"
 
             # Cleanup old images
             docker image prune -f