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/infrastructure/services/oidc_service.rs

@@ -70,6 +70,7 @@ struct IdTokenClaims {
     groups: Option<Vec<String>>,
     nonce: Option<String>,
     picture: Option<String>,
+    locale: Option<String>,
     // Standard JWT fields
     #[allow(dead_code)]
     iss: Option<String>,
@@ -96,6 +97,7 @@ struct UserInfoResponse {
     family_name: Option<String>,
     groups: Option<Vec<String>>,
     picture: Option<String>,
+    locale: Option<String>,
 }
 
 // ============================================================================
@@ -469,6 +471,7 @@ impl OidcServicePort for OidcService {
             family_name: claims.family_name,
             groups: claims.groups.unwrap_or_default(),
             picture: claims.picture,
+            locale: claims.locale,
         })
     }
 
@@ -523,6 +526,7 @@ impl OidcServicePort for OidcService {
             family_name: info.family_name,
             groups: info.groups.unwrap_or_default(),
             picture: info.picture,
+            locale: info.locale,
         })
     }