return postdto from post create

Femto.Database/Migrations/20250518193113_AddUserRole.sql

@@ -6,4 +6,4 @@ CREATE TABLE authn.user_role
     user_id uuid REFERENCES authn.user_identity(id),
     role    int,
     primary key (user_id, role)
-);
+)

Femto.Database/Migrations/20250526220032_AddReactions.sql

@@ -8,5 +8,6 @@ CREATE TABLE blog.post_reaction
 (
     post_id uuid REFERENCES blog.post(id),
     author_id uuid REFERENCES blog.author(id),
-    emoji text not null
+    emoji text not null,
+    primary key (post_id, author_id, emoji)
 );