Stufe 4c (#764): Bezeichner auf Englisch - Typen, Methoden, Felder, Parameter, Locals, Testnamen

Mit Roslyn umbenannt (Verweise folgen, Zeichenketten bleiben unberuehrt).
Nicht umbenannt, weil gespeichert oder ueber die API gebunden (Stufe 4e):
Properties, Record-Parameter, Enum-Member sowie die Parameter der
Endpunkt-Handler (Routen-/Query-Bindung ueber den Namen). Die JSON-Felder
anonymer Objekte bleiben ausdruecklich benannt (JsonFilter: pfad).

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

tests/ClawdDotNet.Core.Tests/Deploymentcenter/InstanceHealthProviderTests.cs

@@ -25,7 +25,7 @@ public sealed class InstanceHealthProviderTests
         new(DateOnly.FromDateTime(DateTime.Now), tokens, 0, cost, true, 1);
 
     [Fact]
-    public async Task Ohne_API_Key_meldet_error()
+    public async Task Without_API_key_reports_error()
     {
         var provider = new InstanceHealthProvider(
             "Test", agentsEnabled: false, InstanceBudget.Unlimited,
@@ -39,7 +39,7 @@ public sealed class InstanceHealthProviderTests
     }
 
     [Fact]
-    public async Task Erschoepftes_Kostenbudget_meldet_warning()
+    public async Task Exhausted_cost_budget_reports_warning()
     {
         var budget = new InstanceBudget { DailyCostUsd = 5m };
         var provider = new InstanceHealthProvider(
@@ -58,7 +58,7 @@ public sealed class InstanceHealthProviderTests
     /// instance no longer works through anything — and exactly that is what the check should make visible.
     /// </summary>
     [Fact]
-    public async Task Stehender_Scanner_meldet_warning()
+    public async Task Stalled_scanner_reports_warning()
     {
         var provider = new InstanceHealthProvider(
             "Test", agentsEnabled: true, InstanceBudget.Unlimited,
@@ -72,7 +72,7 @@ public sealed class InstanceHealthProviderTests
     }
 
     [Fact]
-    public async Task Normalbetrieb_meldet_ok_mit_Metriken()
+    public async Task Normal_operation_reports_ok_with_metrics()
     {
         var provider = new InstanceHealthProvider(
             "Test", agentsEnabled: true, InstanceBudget.Unlimited,
@@ -93,7 +93,7 @@ public sealed class InstanceHealthProviderTests
     /// the history silently discards. Descriptive things belong in the message.
     /// </summary>
     [Fact]
-    public async Task Instanzname_steht_in_der_Meldung_nicht_in_den_Metriken()
+    public async Task Instance_name_is_in_the_message_not_in_the_metrics()
     {
         var provider = new InstanceHealthProvider(
             "Produktion", agentsEnabled: true, InstanceBudget.Unlimited,