feat(user.prefered_locale): save user's locale + invited have same locale as inviters

- OIDC JIT define the locale only at user creation, user can so change his preference later
    - invited users will inherit inviter's locale
    - email will use prefered_locale
    - login to a new browser will use prefered_locale

src/interfaces/api/handlers/auth_handler.rs

@@ -559,7 +559,7 @@ pub async fn update_profile(
 
     let updated = auth_service
         .auth_application_service
-        .update_profile_with_perms(user_id, dto)
+        .update_profile_with_perms(user_id, dto, &state.locale_registry)
         .await?;
 
     Ok((StatusCode::OK, Json(updated)))
@@ -926,7 +926,7 @@ pub async fn oidc_callback(
 
     // Exchange code, validate state/nonce/PKCE, authenticate user
     let result = auth_app
-        .oidc_callback(&query.code, &query.state)
+        .oidc_callback(&query.code, &query.state, &state.locale_registry)
         .await
         .map_err(|e| {
             tracing::error!("OIDC callback failed: {}", e);

src/interfaces/api/handlers/grant_handler.rs

@@ -137,7 +137,14 @@ pub async fn create_grant(
                     state.email_invite_rate_limiter.retry_after(),
                 );
             }
-            match invite_svc.resolve_or_create_recipient(&email).await {
+            // PR C: pass the inviter id so resolve_or_create_recipient
+            // can inherit their preferred_locale onto a freshly-
+            // provisioned external user (best-effort; lookup failure
+            // just leaves the new row's locale NULL, no hard error).
+            match invite_svc
+                .resolve_or_create_recipient(&email, Some(caller_id))
+                .await
+            {
                 Ok(user) => (Subject::User(user.id()), Some(user)),
                 Err(e) => return AppError::from(e).into_response(),
             }