feat: Implement dynamic Gatekeeper proxy and enhance service health monitoring

- **Implemented Dynamic Gatekeeper (Anubis) Proxy:**
  - Introduced Anubis as a Gatekeeper proxy layer for services (`web`, `web-staging`, `feedback`, `health`).
  - Added `docker-gen` setup (`docker-compose_gatekeeper.template.yml`, `gatekeeper-manager`) to dynamically configure Anubis instances based on container labels (`enable_gatekeeper=true`).
  - Updated HAProxy to route traffic through the respective Gatekeeper services.

- **Enhanced Service Health Monitoring & Checks:**
  - Integrated `django-health-check` into the Django application, providing detailed health endpoints (e.g., `/health/`).
  - Replaced the custom health check view with `django-health-check` URLs.
  - Added `psutil` for system metrics in health checks.
  - Made Gatus configuration dynamic using `docker-gen` (`config.template.yaml`), allowing automatic discovery and monitoring of service instances (e.g., web workers).
  - Externalized Gatus SMTP credentials to environment variables.
  - Strengthened `docker-compose_core.yml` with a combined `db-redis-healthcheck` service reporting to Gatus.
  - Added explicit health checks for `db` and `redis` services in `docker-compose.yml`.

- **Improved Docker & Compose Configuration:**
  - Added `depends_on` conditions in `docker-compose.yml` for `web` and `celery` services to wait for the database.
  - Updated `ALLOWED_HOSTS` in `docker-compose_staging.yml` and `docker-compose_web.yml` to include internal container names for Gatekeeper communication.
  - Set `DEBUG=False` for staging services.
  - Removed `.env.production` from `.gitignore` (standardized to `.env`).
  - Streamlined `scripts/entrypoint.sh` by removing the call to the no-longer-present `/deploy.sh`.

- **Dependency Updates:**
  - Added `django-health-check>=3.18.3` and `psutil>=7.0.0` to `pyproject.toml` and `uv.lock`.
  - Updated `settings.py` to include `health_check` apps, configuration, and use `REDIS_URL` consistently.

- **Streamlined deployment script used in GHA:**
  - Updated the workflow to copy new server files and create a new `.env` file in the temporary directory before moving them into place.
  - Consolidated the stopping and removal of old containers into a single step for better clarity and efficiency.
  - Reduce container downtime by rearranging stop/start steps.

server/docker-compose_web.yml

@@ -2,11 +2,6 @@ x-common: &common
   restart: always
   env_file:
     - .env
-  environment:
-    - DEBUG=False
-    - DISABLE_SIGNUPS=True
-    - PUBLIC_HOST=pkmntrade.club
-    - ALLOWED_HOSTS=pkmntrade.club,127.0.0.1
 
 services:
   web:
@@ -15,6 +10,13 @@ services:
     entrypoint: ["/ko-app/httpdebug", "--bind", ":8000"]
     #image: badbl0cks/pkmntrade-club:stable
     #command: ["granian", "--interface", "wsgi", "pkmntrade_club.django_project.wsgi:app", "--host", "0.0.0.0", "--port", "8000", "--workers", "1", "--workers-kill-timeout", "180", "--access-log"] 
+    environment:
+      - DEBUG=False
+      - DISABLE_SIGNUPS=True
+      - PUBLIC_HOST=pkmntrade.club
+      - ALLOWED_HOSTS=pkmntrade.club,127.0.0.1,pkmntrade-club-web-1,pkmntrade-club-web-2,pkmntrade-club-web-3,pkmntrade-club-web-4
+    labels:
+      - "enable_gatekeeper=true"
     deploy:
       mode: replicated
       replicas: 4
@@ -24,7 +26,12 @@ services:
     #   timeout: 10s
     #   retries: 3
     #   start_period: 30s
-  celery:
-    <<: *common
-    image: badbl0cks/pkmntrade-club:stable
-    command: ["celery", "-A", "pkmntrade_club.django_project", "worker", "-l", "INFO", "-B", "-E"]
+  # celery:
+  #   <<: *common
+  #   image: badbl0cks/pkmntrade-club:stable
+  #   environment:
+  #     - DEBUG=False
+  #     - DISABLE_SIGNUPS=True
+  #     - PUBLIC_HOST=pkmntrade.club
+  #     - ALLOWED_HOSTS=pkmntrade.club,127.0.0.1,pkmntrade-club-celery-1,pkmntrade-club-celery-2
+  #   command: ["celery", "-A", "pkmntrade_club.django_project", "worker", "-l", "INFO", "-B", "-E"]