Key-Scanner: Intervall durch tägliche Scan-Uhrzeit ersetzen

- ScanIntervalHours → ScanDailyHour (0-23 = Stunde, -1 = deaktiviert)
- Einmal täglich zur konfigurierten Uhrzeit statt alle X Stunden
- Manueller Trigger funktioniert weiterhin unabhängig
- WaitForTriggerOnly entfernt, vereinfachte Loop-Logik

Services/ServerSettingsService.cs

@@ -33,7 +33,7 @@ public class ServerSettingsService
         new SettingDefinition( "GeminiApiKey",       "string", "",      "Gemini API-Key (für Gemini-Provider im Chat)",                   "password" ),
         new SettingDefinition( "GitHubToken",        "string", "",      "GitHub PAT für Key-Scanner und Code-Search Tool",                "password" ),
         new SettingDefinition( "SerperApiKey",       "string", "",      "Serper.dev API-Key für Google-Suche (Key-Scanner + Tool)",       "password" ),
-        new SettingDefinition( "ScanIntervalHours",  "int",    "0",     "Key-Scanner Intervall in Stunden (0 = nur manuell)",             "number"   ),
+        new SettingDefinition( "ScanDailyHour",      "int",    "-1",    "Key-Scanner Full-Scan Uhrzeit (0-23, -1 = deaktiviert)",         "number"   ),
         new SettingDefinition( "GitHubEventScanner", "bool",   "false", "GitHub Event Scanner (Echtzeit-Monitoring öffentlicher Pushes)", "toggle"   ),
         new SettingDefinition( "HuggingFaceToken",   "string", "",      "HuggingFace Token (optional, erhöht Rate-Limits)",            "password" ),
         new SettingDefinition( "ScannerKeyTypes",    "string_array", "anthropic_oauth,krea_ai", "Key-Scanner: Aktive Key-Typen",                               "checkboxes" ),