Stufe 1 (#764): Agent bearbeiten, Lizenz und Einstellungen in der WebUI

- PUT /api/agents/{id} und /texts: Stammdaten, Grenzen, Budget, Identity/Soul/
  Systemprompt (L6/L7); "Jetzt ausfuehren" in der Agentenansicht (L9)
- Lizenzschluessel ueber die Weboberflaeche (L1): erst vom Lizenzserver
  bestaetigt, dann gespeichert; hebt die Sperre ohne Neustart auf
- GET/PUT /api/settings: Instanz- und Anwendungseinstellungen inkl.
  OpenRouter-Key (L3/L4/L5), Geheimnisse nur schreibend
- GET/PUT /api/verwaltung/settings: Deploymentcenter und Update-Kanal des Managers
- Einstellungsseite zeigt echte Werte statt fester Texte
- NonInteractiveLicensePrompt verwies auf --license-set-key, den es nie gab
- Sprachpakete werden bei jedem Lauf geprueft (LanguagePackTests)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ClawdDotNet.Manager.Web/Endpoints.cs

@@ -74,6 +74,20 @@ public sealed record FtpSettingsUpdateDto(
     bool Enabled, string Host, int Port, string Username, string? Password,
     string RemoteDirectory, bool RequireTls, int KeepCount);
 
+/// <summary>#764: The license as the web interface sees it — never the key, only whether one is set.</summary>
+public sealed record LicenseStatusDto(bool Enforced, bool Holds, bool KeySet, string? HardwareId);
+
+/// <summary>#764: A license key entered in the web interface.</summary>
+public sealed record LicenseKeyDto(string Key);
+
+/// <summary>#764: The manager's own settings — without the master token, only whether one is set.</summary>
+public sealed record ManagerSettingsDto(
+    string ConfigFile, string InstancesDirectory, int WebUiPort, string WebUiBinding,
+    string DeploymentcenterUrl, bool MasterTokenSet, string UpdateChannel);
+
+/// <summary>#764: A change to the manager's settings. <c>null</c> keeps a value, an empty token too.</summary>
+public sealed record ManagerSettingsUpdateDto(string? DeploymentcenterUrl, string? MasterToken, string? UpdateChannel);
+
 /// <summary>
 /// Die HTTP-Fläche des Managers.
 ///
@@ -368,6 +382,37 @@ internal static class ManagerEndpoints
             }
         });
 
+        // ─── License and manager settings (#764) ───
+
+        verwaltung.MapGet("/license", (ManagerCore manager) =>
+            Results.Ok(new LicenseStatusDto(
+                manager.LicenseEnforced, manager.LicenseHolds,
+                !string.IsNullOrWhiteSpace(manager.Settings.LicenseKey), manager.LicenseHardwareId)));
+
+        // The key goes to the license server before it is stored; a refused key leaves the
+        // current one in place (LicenseGate.ApplyKeyAsync).
+        verwaltung.MapPut("/license", async (LicenseKeyDto input, ManagerCore manager, CancellationToken ct) =>
+        {
+            var result = await manager.ApplyLicenseKeyAsync(input.Key ?? "", ct);
+            return result.Applied
+                ? Results.Ok(new OutcomeDto(true, result.Message))
+                : Results.BadRequest(new OutcomeDto(false, result.Message));
+        });
+
+        verwaltung.MapGet("/settings", (ManagerCore manager) =>
+        {
+            var s = manager.Settings;
+            return Results.Ok(new ManagerSettingsDto(
+                manager.SettingsPath, s.InstancesDirectory, s.WebUiPort, s.WebUiBinding,
+                s.DeploymentcenterUrl, !string.IsNullOrWhiteSpace(s.DeploymentcenterMasterToken), s.UpdateChannel));
+        });
+
+        verwaltung.MapPut("/settings", (ManagerSettingsUpdateDto input, ManagerCore manager) =>
+        {
+            var (ok, message) = manager.UpdateSettings(input.DeploymentcenterUrl, input.MasterToken, input.UpdateChannel);
+            return ok ? Results.Ok(new OutcomeDto(true, message)) : Results.BadRequest(new OutcomeDto(false, message));
+        });
+
         // ─── FTP-Upload der Sicherungen ───
 
         verwaltung.MapGet("/sicherung/ftp", (ManagerBackups backups) =>