fix: update test to expect translation key instead of translated string

The test was expecting the actual translated message but since t() is mocked
to return the key, it should expect the translation key instead.

Author: daniel-lxs

src/core/webview/__tests__/webviewMessageHandler.delete.spec.ts

@@ -158,8 +158,8 @@ describe("webviewMessageHandler delete functionality", () => {
 				messageTs: 9999,
 			})
 
-			// Verify error message was shown
-			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("Message with timestamp 9999 not found")
+			// Verify error message was shown (expecting translation key since t() is mocked to return the key)
+			expect(vscode.window.showErrorMessage).toHaveBeenCalledWith("common:errors.message.message_not_found")
 
 			// Verify no truncation occurred
 			expect(getCurrentTaskMock.overwriteClineMessages).not.toHaveBeenCalled()