feat(drive): remove create_home_folder

remove create_home_folder() & ensure_home_folder()

    now: on_user_created() and on_user_login both() call provision_if_needed()
    which calls **create_personal_drive_atomic()**

    add a helper to find Personal drive for a user and also it's root directorry

src/common/stubs.rs

@@ -353,15 +353,6 @@ impl FolderRepository for StubFolderStoragePort {
     async fn delete_folder_permanently(&self, _folder_id: &str) -> Result<(), DomainError> {
         Ok(())
     }
-
-    async fn create_home_folder(
-        &self,
-        _user_id: Uuid,
-        _drive_id: Uuid,
-        _name: String,
-    ) -> Result<Folder, DomainError> {
-        Ok(Folder::default())
-    }
 }
 
 // ---------------------------------------------------------------------------
@@ -495,15 +486,6 @@ impl FolderUseCase for StubFolderUseCase {
     ) -> Result<(), DomainError> {
         Ok(())
     }
-
-    async fn create_home_folder(
-        &self,
-        _user_id: Uuid,
-        _drive_id: Uuid,
-        _name: String,
-    ) -> Result<FolderDto, DomainError> {
-        Ok(FolderDto::default())
-    }
 }
 
 // ---------------------------------------------------------------------------