feat: add Role (owner|admin) to the user domain, persistence model and mapper

features/get_current_user.feature

@@ -11,8 +11,8 @@ Feature: A logged-in user fetches their own public profile without triggering th
   Background:
     Given the public user struct and its converter, shared by the auth and user handlers from a
       package under api/pkg (features/user_display_name.feature), exactly the JSON shape
-      POST /v1/auth/verify returns: id, username, email, is_verified, created_at, updated_at and
-      display_name
+      POST /v1/auth/verify returns: id, username, email, is_verified, created_at, updated_at,
+      display_name and role
     And this slice adds GET /v1/auth/me, handled by a new MeHandler (api/handlers/auth/meHandler.go)
       built with NewMeHandler(container.GetUserUseCase), the same GetUserUseCase every other
       protected handler already gets from api/dependecyInjection.go; no new use case or domain
@@ -43,23 +43,23 @@ Feature: A logged-in user fetches their own public profile without triggering th
 
   Scenario: A verified user fetches their own profile
     Given a user repository containing user id 7, username "alice", email "alice@example.com",
-      is_verified true, TokenVersion 0
+      is_verified true, role "owner", TokenVersion 0
     And a valid jwt cookie for user id 7 encoding token_version 0
     When the client sends GET /v1/auth/me with that cookie
     Then the response status is 200
     And the response header Cache-Control is "no-store"
     And the response body is the user as JSON with id 7, username "alice", email
-      "alice@example.com", is_verified true
+      "alice@example.com", is_verified true, role "owner"
 
   Scenario: An unverified user still fetches their own profile, with is_verified false, not a 403
     Given a user repository containing user id 8, username "bob", email "bob@example.com",
-      is_verified false, TokenVersion 0
+      is_verified false, role "owner", TokenVersion 0
     And a valid jwt cookie for user id 8 encoding token_version 0
     When the client sends GET /v1/auth/me with that cookie
     Then the response status is 200
     And the response header Cache-Control is "no-store"
     And the response body is the user as JSON with id 8, username "bob", email "bob@example.com",
-      is_verified false
+      is_verified false, role "owner"
 
   Scenario: No jwt cookie at all is refused
     Given a user repository containing user id 7, username "alice", is_verified true, TokenVersion 0