feat: cache same-turn approval selections

Add an AlwaysApprove flag to resolve-approval commands and cache
approved tool keys for the current request so repeated runtime
permissions are auto-approved immediately within the same turn.
The cache is cleared when the turn finishes to avoid leaking across
future requests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

sidecar/src/Aryx.AgentHost/Services/CopilotWorkflowRunner.cs

@@ -111,6 +111,10 @@ public sealed class CopilotWorkflowRunner : ITurnWorkflowRunner
             await onExitPlanMode(exitPlanModeEvent).ConfigureAwait(false);
             return state.FinalizeCompletedMessages();
         }
+        finally
+        {
+            _approvalCoordinator.ClearRequestApprovals(command.RequestId);
+        }
     }
 
     private static async Task EmitPendingActivityEventsAsync(