fix(mobile): URL changement mdp corrigée + v3.0 — multi-org, AppAuth, sécurité prod

Auth:
- profile_repository.dart: /api/auth/change-password → /api/membres/auth/change-password

Multi-org (Phase 3):
- OrgSelectorPage, OrgSwitcherBloc, OrgSwitcherEntry
- org_context_service.dart: headers X-Active-Organisation-Id + X-Active-Role

Navigation:
- MorePage: navigation conditionnelle par typeOrganisation
- Suppression adaptive_navigation (remplacé par main_navigation_layout)

Auth AppAuth:
- keycloak_webview_auth_service: fixes AppAuth Android
- AuthBloc: gestion REAUTH_REQUIS + premierLoginComplet

Onboarding:
- Nouveaux états: payment_method_page, onboarding_shared_widgets
- SouscriptionStatusModel mis à jour StatutValidationSouscription

Android:
- build.gradle: ProGuard/R8, network_security_config
- Gradle wrapper mis à jour

android/settings.gradle

@@ -18,8 +18,8 @@ pluginManagement {
 
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "8.1.0" apply false
-    id "org.jetbrains.kotlin.android" version "1.8.22" apply false
+    id "com.android.application" version "8.7.3" apply false
+    id "org.jetbrains.kotlin.android" version "2.1.0" apply false
 }
 
 include ":app"