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/messaging/channels/__init__.py

@@ -0,0 +1,29 @@
+"""Channel dispatch — email / SMS / postcard."""
+
+from dataclasses import dataclass
+
+from contacts.models import Channel
+from messaging.models import Message
+from messaging.providers.email.smtp2go import send_email
+from messaging.providers.postcard import get_postcard_provider
+from messaging.providers.sms.smtp2go import send_sms
+
+
+@dataclass
+class ProviderResult:
+    provider: str
+    provider_id: str
+
+
+def dispatch_message(message: Message) -> ProviderResult:
+    if message.channel == Channel.EMAIL:
+        result = send_email(message)
+        return ProviderResult(provider="smtp2go_email", provider_id=result)
+    if message.channel == Channel.SMS:
+        result = send_sms(message)
+        return ProviderResult(provider="smtp2go_sms", provider_id=result)
+    if message.channel == Channel.POSTCARD:
+        provider = get_postcard_provider()
+        result = provider.send_postcard(message)
+        return ProviderResult(provider=provider.name, provider_id=result.provider_id)
+    raise ValueError(f"Unsupported channel: {message.channel}")