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>

kboris/settings.py

@@ -12,6 +12,7 @@ ALLOWED_HOSTS = [
     'admin.k-boris.tech',
     'killmybacklog.com',
     'www.killmybacklog.com',
+    'debug.killmybacklog.com',
     'localhost',
     '127.0.0.1',
 ]
@@ -22,6 +23,7 @@ CSRF_TRUSTED_ORIGINS = [
     'https://admin.k-boris.tech',
     'https://killmybacklog.com',
     'https://www.killmybacklog.com',
+    'https://debug.killmybacklog.com',
 ]
 
 INSTALLED_APPS = [