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)

Services/GoogleKeyChecker.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Linq;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace Gott.Services
+{
+    public class GoogleCheckResult
+    {
+        public string Status { get; set; }     // "ok", "invalid", "disabled", "error"
+        public string Message { get; set; }
+        public string[] Models { get; set; }
+    }
+
+    public static class GoogleKeyChecker
+    {
+        public static async Task<GoogleCheckResult> CheckKeyAsync(IHttpClientFactory httpFactory, string apiKey)
+        {
+            try
+            {
+                var client = httpFactory.CreateClient();
+                client.Timeout = TimeSpan.FromSeconds(30);
+
+                // Gemini / Generative Language API – listet verfügbare Modelle
+                var url = "https://generativelanguage.googleapis.com/v1/models?key=" + apiKey;
+                var resp = await client.GetAsync(url);
+                var statusCode = (int)resp.StatusCode;
+
+                if (statusCode == 400)
+                    return new GoogleCheckResult { Status = "invalid", Message = "API-Key ungültig (400)" };
+
+                if (statusCode == 403)
+                {
+                    // Key gültig, aber Gemini API nicht aktiviert (z.B. Maps-Key)
+                    var errorBody = await resp.Content.ReadAsStringAsync();
+                    if (errorBody.Contains("API_KEY_INVALID", StringComparison.OrdinalIgnoreCase))
+                        return new GoogleCheckResult { Status = "invalid", Message = "API-Key ungültig (403)" };
+
+                    return new GoogleCheckResult { Status = "disabled", Message = "Key gültig, aber Gemini API nicht aktiviert (403)" };
+                }
+
+                if (statusCode == 429)
+                    return new GoogleCheckResult { Status = "rate_limited", Message = "Rate Limited (429)" };
+
+                if (statusCode >= 400)
+                    return new GoogleCheckResult { Status = "error", Message = "API-Fehler (" + statusCode + ")" };
+
+                // 200 OK → Key gültig + Gemini API aktiv
+                var body = await resp.Content.ReadAsStringAsync();
+                var doc = JsonDocument.Parse(body);
+
+                string[] models = Array.Empty<string>();
+                if (doc.RootElement.TryGetProperty("models", out var modelsArr))
+                {
+                    var interestingPrefixes = new[] { "gemini" };
+                    models = modelsArr.EnumerateArray()
+                        .Where(m => m.TryGetProperty("name", out _))
+                        .Select(m => m.GetProperty("name").GetString())
+                        .Where(n => n != null)
+                        .Select(n => n.StartsWith("models/", StringComparison.Ordinal) ? n.Substring(7) : n)
+                        .Where(n => interestingPrefixes.Any(p => n.StartsWith(p, StringComparison.OrdinalIgnoreCase)))
+                        .Distinct()
+                        .OrderBy(x => x)
+                        .ToArray();
+                }
+
+                // Plan-Erkennung
+                string plan;
+                if (models.Any(m => m.Contains("2.5", StringComparison.OrdinalIgnoreCase)
+                                 || m.Contains("ultra", StringComparison.OrdinalIgnoreCase)))
+                    plan = "Premium";
+                else if (models.Any(m => m.Contains("pro", StringComparison.OrdinalIgnoreCase)))
+                    plan = "Standard";
+                else if (models.Any(m => m.Contains("flash", StringComparison.OrdinalIgnoreCase)))
+                    plan = "Basic";
+                else
+                    plan = "Free";
+
+                return new GoogleCheckResult
+                {
+                    Status = "ok",
+                    Message = models.Length + " Gemini-Modelle · " + plan,
+                    Models = models
+                };
+            }
+            catch (Exception ex)
+            {
+                return new GoogleCheckResult { Status = "error", Message = ex.Message };
+            }
+        }
+    }
+}