fix(db): remove role_key column alias breaking every ProfessionalRepository query

All three queries selected role_key AS profession_key, but the Professional
struct's field is named role_key — sqlx's FromRow derive matches by column
name, so every call (get_by_user_id, submit_for_verification, and its
UPDATE...RETURNING) failed at runtime with "no column found for name:
role_key". This is the professional-profile existence check used by
document upload, portfolio, and submission endpoints across all 10
profession services — document upload was 500ing for every professional
role because of this.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/db/src/models/professional.rs

@@ -110,7 +110,7 @@ pub struct ProfessionalRepository;
 impl ProfessionalRepository {
     pub async fn get_by_user_id(pool: &PgPool, user_id: Uuid) -> Result<Professional, sqlx::Error> {
         sqlx::query_as::<_, Professional>(
-            "SELECT id, user_id, role_key as profession_key, status, created_at, updated_at FROM user_role_profiles WHERE user_id = $1 AND role_key != 'CUSTOMER' AND role_key != 'COMPANY'",
+            "SELECT id, user_id, role_key, status, created_at, updated_at FROM user_role_profiles WHERE user_id = $1 AND role_key != 'CUSTOMER' AND role_key != 'COMPANY'",
         )
         .bind(user_id)
         .fetch_one(pool)
@@ -556,7 +556,7 @@ impl ProfessionalRepository {
         profession_key: &str,
     ) -> Result<Professional, sqlx::Error> {
         let prof = sqlx::query_as::<_, Professional>(
-            "SELECT id, user_id, role_key as profession_key, status, created_at, updated_at FROM user_role_profiles WHERE user_id = $1 AND role_key = $2",
+            "SELECT id, user_id, role_key, status, created_at, updated_at FROM user_role_profiles WHERE user_id = $1 AND role_key = $2",
         )
         .bind(user_id)
         .bind(profession_key)
@@ -572,7 +572,7 @@ impl ProfessionalRepository {
             UPDATE user_role_profiles
             SET status = 'PENDING_REVIEW', updated_at = NOW()
             WHERE user_id = $1 AND role_key = $2
-            RETURNING id, user_id, role_key as profession_key, status, created_at, updated_at
+            RETURNING id, user_id, role_key, status, created_at, updated_at
             "#,
         )
         .bind(user_id)