Add dev environment: debug subdomain, IP restriction, separate container

- Add debug.killmybacklog.com nginx config (IP-restricted to 164.215.8.152)
- Add django-dev container on port 8081 in docker-compose
- Add dev branch pipeline step deploying to django-dev
- Add killmybacklog.com and debug subdomain to ALLOWED_HOSTS/CSRF origins

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

.woodpecker.yml

@@ -1,6 +1,6 @@
 when:
-  branch: main
   event: [push, manual]
+  branch: [main, dev]
 
 steps:
   test:
@@ -10,7 +10,6 @@ steps:
       - python manage.py test backlogger --verbosity=2
     environment:
       DJANGO_SECRET_KEY: ci-test-key
-      DATABASE_URL: sqlite:///tmp/test.db
 
   build-and-deploy:
     image: docker:cli
@@ -23,3 +22,19 @@ steps:
       - docker build -t k-boris-website /opt/services/app/
       - docker compose -f /opt/services/docker-compose.yml up -d --no-deps django
     depends_on: [test]
+    when:
+      branch: main
+
+  build-and-deploy-dev:
+    image: docker:cli
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - /opt/services:/opt/services
+    commands:
+      - mkdir -p /opt/services/app-dev
+      - cp -r . /opt/services/app-dev/
+      - docker build -t k-boris-website-dev /opt/services/app-dev/
+      - docker compose -f /opt/services/docker-compose.yml up -d --no-deps django-dev
+    depends_on: [test]
+    when:
+      branch: dev