User-spezifische API-Key-Auswahl, globales is_active entfernt

Backend:
- is_active komplett entfernt, durch is_public (Admin-Toggle) ersetzt
- Neues selected_api_key_id auf users-Tabelle
- AnthropicService: globaler _token entfernt, apiToken pro Request
- Token-Durchreichung: StreamChat → ProcessStream → RunAgentChat →
  RunPreparer/RunReview/RunFinalizer, ExecuteTool, send_to_session
- ChatEndpoint: User-Key aus DB laden, an StreamChat übergeben
- TelegramService: Key per bot.UserId auflösen
- CronjobService: Key per job.UserId auflösen
- Neue Endpoints: GET /api/api-keys/available, PUT /api/api-keys/select/{keyId},
  GET /api/api-keys/selected, PUT /api/admin/api-keys/{keyId}/public,
  POST /api/admin/api-keys/check-all
- Program.cs: AnthropicService ohne Token-Parameter

Frontend:
- API-Keys-Page: Public-Toggle (Globe/Lock) statt Activate/Deactivate
- Alle prüfen Button für Batch-Key-Check
- Chat: Key-Auswahl für alle User (nicht nur Admin)
- Dummy-Badge wenn kein Key ausgewählt
- Fallback-Badge bei Key ohne Usage-Daten
- Key-Switch-Modal: apiGetAvailableKeys + apiSelectApiKey

Services/DatabaseService.Integrations.cs

@@ -324,7 +324,7 @@ public partial class DatabaseService
                         {
                             var now = DateTime.UtcNow.ToString("o");
                             conn.Execute(@"
-                                INSERT INTO api_keys (key_id, provider, name, api_key, is_active, created_at, updated_at)
+                                INSERT INTO api_keys (key_id, provider, name, api_key, is_public, created_at, updated_at)
                                 VALUES (@keyId, 'anthropic', 'Migriert aus Config', @token, 1, @now, @now)",
                                 new { keyId = Guid.NewGuid().ToString("N"), token, now });
                             Console.WriteLine("[Migration] AnthropicToken aus appsettings.Production.json → api_keys migriert");
@@ -351,12 +351,11 @@ public partial class DatabaseService
             new { provider });
     }
 
-    public async Task<ApiKeyRecord> GetActiveApiKey(string provider)
+    public async Task<IEnumerable<ApiKeyRecord>> GetPublicApiKeys()
     {
         using var conn = CreateConnection();
-        return await conn.QuerySingleOrDefaultAsync<ApiKeyRecord>(
-            "SELECT * FROM api_keys WHERE provider = @provider AND is_active = 1 LIMIT 1",
-            new { provider });
+        return await conn.QueryAsync<ApiKeyRecord>(
+            "SELECT * FROM api_keys WHERE is_public = 1 ORDER BY provider, name");
     }
 
     public async Task<ApiKeyRecord> GetApiKey(string keyId)
@@ -372,8 +371,8 @@ public partial class DatabaseService
     {
         using var conn = CreateConnection();
         await conn.ExecuteAsync(@"
-            INSERT INTO api_keys (key_id, provider, name, api_key, is_active, status, plan, usage_7d, usage_5h, checked_at, source_url, created_at, updated_at)
-            VALUES (@KeyId, @Provider, @Name, @ApiKey, @IsActive, @Status, @Plan, @Usage7d, @Usage5h, @CheckedAt, @SourceUrl, @CreatedAt, @UpdatedAt)",
+            INSERT INTO api_keys (key_id, provider, name, api_key, is_public, status, plan, usage_7d, usage_5h, checked_at, source_url, created_at, updated_at)
+            VALUES (@KeyId, @Provider, @Name, @ApiKey, @IsPublic, @Status, @Plan, @Usage7d, @Usage5h, @CheckedAt, @SourceUrl, @CreatedAt, @UpdatedAt)",
             record);
         return await conn.ExecuteScalarAsync<long>("SELECT last_insert_rowid()");
     }
@@ -409,29 +408,16 @@ public partial class DatabaseService
         using var conn = CreateConnection();
         await conn.ExecuteAsync(@"
             UPDATE api_keys SET status = @status, plan = @plan, usage_7d = @usage7d, usage_5h = @usage5h, checked_at = @now, updated_at = @now
-            WHERE api_key = @apiKey AND is_active = 1",
+            WHERE api_key = @apiKey",
             new { apiKey, status, plan, usage7d, usage5h, now = DateTime.UtcNow.ToString("o") });
     }
 
-    public async Task SetActiveApiKey(string keyId, string provider)
-    {
-        using var conn = CreateConnection();
-        // Erst alle deaktivieren
-        await conn.ExecuteAsync(
-            "UPDATE api_keys SET is_active = 0, updated_at = @now WHERE provider = @provider",
-            new { provider, now = DateTime.UtcNow.ToString("o") });
-        // Dann den gewählten aktivieren
-        await conn.ExecuteAsync(
-            "UPDATE api_keys SET is_active = 1, updated_at = @now WHERE key_id = @keyId",
-            new { keyId, now = DateTime.UtcNow.ToString("o") });
-    }
-
-    public async Task DeactivateApiKey(string keyId)
+    public async Task SetApiKeyPublic(string keyId, bool isPublic)
     {
         using var conn = CreateConnection();
         await conn.ExecuteAsync(
-            "UPDATE api_keys SET is_active = 0, updated_at = @now WHERE key_id = @keyId",
-            new { keyId, now = DateTime.UtcNow.ToString("o") });
+            "UPDATE api_keys SET is_public = @isPublic, updated_at = @now WHERE key_id = @keyId",
+            new { keyId, isPublic, now = DateTime.UtcNow.ToString("o") });
     }
 
     public async Task DeleteApiKey(string keyId)