Multi-Provider Key Scanner + Checker (OpenAI, Google, 15 Key-Typen)

- KeyPatterns.cs: Zentrale Pattern-Klasse für 15 Key-Typen
  (Anthropic, OpenAI, Google, AWS, GitHub, GitLab, HuggingFace, Stripe, SendGrid, Slack)
- OpenAiKeyChecker.cs: Prüft sk-proj/sk-svcacct/sk- Keys via /v1/models
  (Org, Modelle, RPM/TPM, Tier-Erkennung Free bis 5+)
- GoogleKeyChecker.cs: Prüft AIza-Keys via Gemini /v1/models
  (Gemini-Modelle, Maps-Key-Erkennung)
- KeyScannerService + GitHubEventScannerService: Dispatch nach Key-Typ
- ApiKeysEndpoint: GET /scanned/summary + ?type= Filter
- Frontend: 2-stufige UI (Typ-Übersicht → Keys pro Typ)

Endpoints/ApiKeysEndpoint.cs

@@ -29,6 +29,7 @@ public static class ApiKeysEndpoint
         app.MapPost("/api/admin/api-keys/scan", HandleScanTrigger);
         app.MapGet("/api/admin/api-keys/scan/status", HandleScanStatus);
         app.MapGet("/api/admin/api-keys/scanned", HandleGetScanned);
+        app.MapGet("/api/admin/api-keys/scanned/summary", HandleGetScannedSummary);
         app.MapPost("/api/admin/api-keys/scanned/recheck-all", HandleRecheckAll);
         app.MapPost("/api/admin/api-keys/scanned/{id}/recheck", HandleRecheck);
         app.MapPost("/api/admin/api-keys/scanned/{id}/adopt", HandleAdopt);
@@ -261,7 +262,11 @@ public static class ApiKeysEndpoint
     {
         if (!ctx.IsAdmin()) { ctx.Response.StatusCode = 403; return; }
 
-        var keys = await db.GetScannedKeys();
+        var type = ctx.Request.Query["type"].FirstOrDefault();
+        var keys = string.IsNullOrEmpty(type)
+            ? await db.GetScannedKeys()
+            : await db.GetScannedKeysByType(type);
+
         var result = keys.Select(k => new
         {
             k.ScannedKeyId,
@@ -279,6 +284,14 @@ public static class ApiKeysEndpoint
         await ctx.Response.WriteAsJsonAsync(result);
     }
 
+    private static async Task HandleGetScannedSummary(HttpContext ctx, DatabaseService db)
+    {
+        if (!ctx.IsAdmin()) { ctx.Response.StatusCode = 403; return; }
+
+        var summary = await db.GetScannedKeysSummary();
+        await ctx.Response.WriteAsJsonAsync(summary);
+    }
+
     private static async Task HandleRecheckAll(HttpContext ctx, DatabaseService db, KeyScannerService scanner)
     {
         if (!ctx.IsAdmin()) { ctx.Response.StatusCode = 403; return; }