feat: BLoC tests complets + sécurité production + freerasp 7.5.1 migration

## Tests BLoC (Task P2.4 Mobile)
- 25 nouveaux fichiers *_bloc_test.dart + mocks générés (build_runner)
- Features couvertes : authentication, admin_users, adhesions, backup,
  communication/messaging, contributions, dashboard, finance (approval/budget),
  events, explore/network, feed, logs_monitoring, notifications, onboarding,
  organizations (switcher/types/CRUD), profile, reports, settings, solidarity
- ~380 tests, > 80% coverage BLoCs

## Sécurité Production (Task P2.2)
- lib/core/security/app_integrity_service.dart (freerasp 7.5.1)
- Migration API breaking changes freerasp 7.5.1 :
  - onRootDetected → onPrivilegedAccess
  - onDebuggerDetected → onDebug
  - onSignatureDetected → onAppIntegrity
  - onHookDetected → onHooks
  - onEmulatorDetected → onSimulator
  - onUntrustedInstallationSourceDetected → onUnofficialStore
  - onDeviceBindingDetected → onDeviceBinding
  - onObfuscationIssuesDetected → onObfuscationIssues
  - Talsec.start() split → start() + attachListener()
  - const AndroidConfig/IOSConfig → final (constructors call ConfigVerifier)
  - supportedAlternativeStores → supportedStores

## Pubspec
- bloc_test: ^9.1.7 → ^10.0.0 (compat flutter_bloc ^9.0.0)
- freerasp 7.5.1

## Config
- android/app/build.gradle : ajustements release
- lib/core/config/environment.dart : URLs API actualisées
- lib/main.dart + app_router : intégrations sécurité/BLoC

## Cleanup
- Suppression docs intermédiaires (TACHES_*.md, TASK_*_COMPLETION_REPORT.md,
  TESTS_UNITAIRES_PROGRESS.md)
- .g.dart régénérés (json_serializable)
- .mocks.dart régénérés (mockito)

## Résultat
- 142 fichiers, +27 596 insertions
- Toutes les tâches P2 mobile complétées

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/app/build.gradle

@@ -94,11 +94,23 @@ android {
         ]
     }
 
+    signingConfigs {
+        release {
+            def keystoreProperties = new Properties()
+            def keystorePropertiesFile = rootProject.file('key.properties')
+            if (keystorePropertiesFile.exists()) {
+                keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
+                keyAlias keystoreProperties['keyAlias']
+                keyPassword keystoreProperties['keyPassword']
+                storeFile file(keystoreProperties['storeFile'])
+                storePassword keystoreProperties['storePassword']
+            }
+        }
+    }
+
     buildTypes {
         release {
-            // TODO: Configurer signingConfigs.release avec votre keystore de production
-            // signingConfig = signingConfigs.release
-            signingConfig = signingConfigs.debug
+            signingConfig = signingConfigs.release
 
             // Activer la minification et l'obfuscation pour la release
             minifyEnabled true