Land CSOC-WP-0006 PageOps: member space/page CRUD, copy, transfer

Thin CONTENT_ROOT content plane (ADR-0003/0004) with space visual field,
product UI for Title/Abstract/Visual, page list sidebar, and tests. Update
capability model and smoke checklist; mark WP-0006 finished.

coulomb_social/apps/spaces/admin.py

@@ -16,15 +16,29 @@ class SpaceAdmin(admin.ModelAdmin):
         "slug",
         "tenant_id",
         "is_active",
+        "visual",
         "forgejo_owner",
         "forgejo_repo",
         "updated_at",
     )
     list_filter = ("tenant_id", "is_active")
-    search_fields = ("title", "slug", "forgejo_repo")
+    search_fields = ("title", "slug", "description", "forgejo_repo")
     prepopulated_fields = {"slug": ("title",)}
     raw_id_fields = ("created_by",)
     inlines = [SpaceMembershipInline]
+    fields = (
+        "tenant_id",
+        "slug",
+        "title",
+        "description",
+        "visual",
+        "created_by",
+        "forgejo_owner",
+        "forgejo_repo",
+        "default_branch",
+        "content_root",
+        "is_active",
+    )
 
 
 @admin.register(SpaceMembership)