Improve outreach compose, contact merge, and email assets.

Add a Quill email editor with DB-backed image storage, selectable PCM designs, postcard defaults for addressed contacts, and merge-by-phone/address on the contact form.

site/messaging/admin.py

@@ -1,6 +1,6 @@
 from django.contrib import admin
 
-from messaging.models import Campaign, Message, MessageTemplate, ProviderEvent
+from messaging.models import Campaign, Message, MessageTemplate, ProviderEvent, StoredFile
 
 
 @admin.register(MessageTemplate)
@@ -38,3 +38,10 @@ class MessageAdmin(admin.ModelAdmin):
 @admin.register(ProviderEvent)
 class ProviderEventAdmin(admin.ModelAdmin):
     list_display = ("provider", "event_type", "created_at")
+
+
+@admin.register(StoredFile)
+class StoredFileAdmin(admin.ModelAdmin):
+    list_display = ("filename", "kind", "content_type", "size", "created_at")
+    list_filter = ("kind", "content_type")
+    readonly_fields = ("size", "content_type", "created_at", "updated_at")