Add Django site, Docker packaging, and beta/prod Gitea deploys.

Unignore site/ (was blocked by mkdocs /site rule), add compose/Docker/uv tooling, and split deploys so push to main goes to beta while prod stays manual.

.gitignore

@@ -137,8 +137,8 @@ venv.bak/
 # Rope project settings
 .ropeproject
 
-# mkdocs documentation
-/site
+# mkdocs documentation (do not use /site — that is the Django project tree)
+/mkdocs_site/
 
 # mypy
 .mypy_cache/
@@ -167,3 +167,4 @@ cython_debug/
 # PyPI configuration file
 .pypirc
 
+.ux-compare/