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.

site/social/admin.py

@@ -0,0 +1,21 @@
+from django.contrib import admin
+
+from social.models import SocialAccount, SocialPost, SocialPostTarget
+
+
+class SocialPostTargetInline(admin.TabularInline):
+    model = SocialPostTarget
+    extra = 0
+
+
+@admin.register(SocialAccount)
+class SocialAccountAdmin(admin.ModelAdmin):
+    list_display = ("label", "platform", "is_active", "external_id")
+    list_filter = ("platform", "is_active")
+
+
+@admin.register(SocialPost)
+class SocialPostAdmin(admin.ModelAdmin):
+    list_display = ("pk", "status", "scheduled_for", "created_at")
+    list_filter = ("status",)
+    inlines = [SocialPostTargetInline]