feat(mobile): Implement Keycloak WebView authentication with HTTP callback

- Replace flutter_appauth with custom WebView implementation to resolve deep link issues
- Add KeycloakWebViewAuthService with integrated WebView for seamless authentication
- Configure Android manifest for HTTP cleartext traffic support
- Add network security config for development environment (192.168.1.11)
- Update Keycloak client to use HTTP callback endpoint (http://192.168.1.11:8080/auth/callback)
- Remove obsolete keycloak_auth_service.dart and temporary scripts
- Clean up dependencies and regenerate injection configuration
- Tested successfully on multiple Android devices (Xiaomi 2201116TG, SM A725F)

BREAKING CHANGE: Authentication flow now uses WebView instead of external browser
- Users will see Keycloak login page within the app instead of browser redirect
- Resolves ERR_CLEARTEXT_NOT_PERMITTED and deep link state management issues
- Maintains full OIDC compliance with PKCE flow and secure token storage

Technical improvements:
- WebView with custom navigation delegate for callback handling
- Automatic token extraction and user info parsing from JWT
- Proper error handling and user feedback
- Consistent authentication state management across app lifecycle

verify-keycloak-config.ps1

@@ -0,0 +1,108 @@
+# Script de verification de la configuration Keycloak
+$KeycloakUrl = "http://192.168.1.11:8180"
+$Realm = "unionflow"
+$ClientId = "unionflow-mobile"
+$Username = "test@unionflow.dev"
+
+Write-Host "=== VERIFICATION CONFIGURATION KEYCLOAK ===" -ForegroundColor Cyan
+Write-Host "Keycloak URL: $KeycloakUrl" -ForegroundColor Gray
+Write-Host "Realm: $Realm" -ForegroundColor Gray
+Write-Host "Client: $ClientId" -ForegroundColor Gray
+Write-Host "User: $Username" -ForegroundColor Gray
+Write-Host ""
+
+# 1. Test de connectivite Keycloak
+Write-Host "1. Test connectivite Keycloak..." -ForegroundColor Yellow
+try {
+    $response = Invoke-WebRequest -Uri "$KeycloakUrl" -Method Get -TimeoutSec 10
+    if ($response.StatusCode -eq 200) {
+        Write-Host "   ✅ Keycloak accessible" -ForegroundColor Green
+    }
+} catch {
+    Write-Host "   ❌ Keycloak non accessible: $($_.Exception.Message)" -ForegroundColor Red
+    exit 1
+}
+
+# 2. Test du realm
+Write-Host "2. Test du realm '$Realm'..." -ForegroundColor Yellow
+try {
+    $realmConfig = Invoke-RestMethod -Uri "$KeycloakUrl/realms/$Realm/.well-known/openid_configuration" -Method Get
+    Write-Host "   ✅ Realm '$Realm' existe et fonctionne" -ForegroundColor Green
+    Write-Host "   Authorization endpoint: $($realmConfig.authorization_endpoint)" -ForegroundColor Gray
+    Write-Host "   Token endpoint: $($realmConfig.token_endpoint)" -ForegroundColor Gray
+} catch {
+    Write-Host "   ❌ Realm '$Realm' non accessible" -ForegroundColor Red
+    exit 1
+}
+
+# 3. Test authentification admin
+Write-Host "3. Test authentification admin..." -ForegroundColor Yellow
+try {
+    $tokenBody = "username=admin&password=admin&grant_type=password&client_id=admin-cli"
+    $tokenResponse = Invoke-RestMethod -Uri "$KeycloakUrl/realms/master/protocol/openid-connect/token" -Method Post -ContentType "application/x-www-form-urlencoded" -Body $tokenBody
+    $accessToken = $tokenResponse.access_token
+    Write-Host "   ✅ Authentification admin reussie" -ForegroundColor Green
+} catch {
+    Write-Host "   ❌ Echec authentification admin" -ForegroundColor Red
+    exit 1
+}
+
+# 4. Verification du client mobile
+Write-Host "4. Verification du client '$ClientId'..." -ForegroundColor Yellow
+try {
+    $headers = @{ "Authorization" = "Bearer $accessToken" }
+    $clients = Invoke-RestMethod -Uri "$KeycloakUrl/admin/realms/$Realm/clients?clientId=$ClientId" -Method Get -Headers $headers
+    
+    if ($clients.Count -gt 0) {
+        $client = $clients[0]
+        Write-Host "   ✅ Client '$ClientId' existe" -ForegroundColor Green
+        Write-Host "   Client ID: $($client.clientId)" -ForegroundColor Gray
+        Write-Host "   Enabled: $($client.enabled)" -ForegroundColor Gray
+        Write-Host "   Public Client: $($client.publicClient)" -ForegroundColor Gray
+        Write-Host "   Standard Flow: $($client.standardFlowEnabled)" -ForegroundColor Gray
+        
+        # Verification des redirect URIs
+        if ($client.redirectUris -contains "com.unionflow.mobile://login-callback/*") {
+            Write-Host "   ✅ Redirect URI mobile configure" -ForegroundColor Green
+        } else {
+            Write-Host "   ⚠️ Redirect URI mobile manquant" -ForegroundColor Yellow
+            Write-Host "   URIs actuelles: $($client.redirectUris -join ', ')" -ForegroundColor Gray
+        }
+    } else {
+        Write-Host "   ❌ Client '$ClientId' non trouve" -ForegroundColor Red
+    }
+} catch {
+    Write-Host "   ❌ Erreur verification client: $($_.Exception.Message)" -ForegroundColor Red
+}
+
+# 5. Verification de l'utilisateur
+Write-Host "5. Verification de l'utilisateur '$Username'..." -ForegroundColor Yellow
+try {
+    $users = Invoke-RestMethod -Uri "$KeycloakUrl/admin/realms/$Realm/users?email=$Username" -Method Get -Headers $headers
+    
+    if ($users.Count -gt 0) {
+        $user = $users[0]
+        Write-Host "   ✅ Utilisateur '$Username' existe" -ForegroundColor Green
+        Write-Host "   Username: $($user.username)" -ForegroundColor Gray
+        Write-Host "   Email: $($user.email)" -ForegroundColor Gray
+        Write-Host "   Enabled: $($user.enabled)" -ForegroundColor Gray
+        Write-Host "   Email Verified: $($user.emailVerified)" -ForegroundColor Gray
+    } else {
+        Write-Host "   ❌ Utilisateur '$Username' non trouve" -ForegroundColor Red
+    }
+} catch {
+    Write-Host "   ❌ Erreur verification utilisateur: $($_.Exception.Message)" -ForegroundColor Red
+}
+
+Write-Host ""
+Write-Host "=== VERIFICATION TERMINEE ===" -ForegroundColor Cyan
+Write-Host ""
+Write-Host "Configuration mobile app:" -ForegroundColor Yellow
+Write-Host "- Keycloak URL: http://192.168.1.11:8180" -ForegroundColor Gray
+Write-Host "- Realm: unionflow" -ForegroundColor Gray
+Write-Host "- Client ID: unionflow-mobile" -ForegroundColor Gray
+Write-Host "- Redirect URI: com.unionflow.mobile://login-callback" -ForegroundColor Gray
+Write-Host ""
+Write-Host "Identifiants de test:" -ForegroundColor Yellow
+Write-Host "- Email: test@unionflow.dev" -ForegroundColor Gray
+Write-Host "- Password: test123" -ForegroundColor Gray