Add deploy script and update prod compose

Deploy script builds and pushes images to Gitea registry, then triggers
Portainer stack redeployment via API. Includes preflight checks for
branch and uncommitted changes. Also renames prod DB volume to avoid
conflicts with dev and changes frontend port to 9080.

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

docker-compose.prod.yml

@@ -1,9 +1,6 @@
 services:
   api:
-    image: gitea.nerdboden.de/julian/nuzlocke-tracker-api:latest
-    build:
-      context: ./backend
-      dockerfile: Dockerfile.prod
+    image: gitea.nerdboden.de/thefurya/nuzlocke-tracker-api:latest
     command: >
       sh -c "alembic upgrade head && uvicorn app.main:app --host 0.0.0.0 --port 8000 --app-dir src"
     environment:
@@ -15,12 +12,9 @@ services:
     restart: unless-stopped
 
   frontend:
-    image: gitea.nerdboden.de/julian/nuzlocke-tracker-frontend:latest
-    build:
-      context: ./frontend
-      dockerfile: Dockerfile.prod
+    image: gitea.nerdboden.de/thefurya/nuzlocke-tracker-frontend:latest
     ports:
-      - "8080:80"
+      - "9080:80"
     depends_on:
       - api
     restart: unless-stopped
@@ -32,7 +26,7 @@ services:
       - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
       - POSTGRES_DB=nuzlocke
     volumes:
-      - postgres_data:/var/lib/postgresql/data
+      - prod_postgres_data:/var/lib/postgresql/data
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U postgres"]
       interval: 5s
@@ -41,4 +35,4 @@ services:
     restart: unless-stopped
 
 volumes:
-  postgres_data:
+  prod_postgres_data: