feat(gui): enhance SHA display logic in UpdateDialog

- Introduce a new class method to display the available SHA or indicate "Current" when up to date.
- Update the new version label to use the new display method for better clarity.
- Adjust the label to show "Current" directly when no pending SHA is available.
- Add unit tests to verify the new display logic for available versions.

gui/main.py

@@ -533,6 +533,10 @@ class UpdateDialog(QDialog):
             return "Unknown"
         return sha[:8]
 
+    @classmethod
+    def _available_sha_display(cls, sha: str | None) -> str:
+        return cls._short_sha(sha) if sha else "Current"
+
     @classmethod
     def _installed_sha_display(cls) -> str:
         return cls._short_sha(UpdateThread.read_installed_sha())
@@ -588,7 +592,7 @@ class UpdateDialog(QDialog):
         self.cancel_btn.setText("Close")
 
         tool_sha = self._pending_tool_sha
-        self.new_version_label.setText(self._short_sha(tool_sha))
+        self.new_version_label.setText(self._available_sha_display(tool_sha))
 
         if not tool_sha:
             self.headline_label.setText("You're up to date")
@@ -642,7 +646,7 @@ class UpdateDialog(QDialog):
                 f"No newer build found on {UpdateThread.REPO_BRANCH}."
             )
             self.subtitle_label.setText("You're running the latest version.")
-            self.new_version_label.setText(self._installed_sha_display())
+            self.new_version_label.setText("Current")
         elif message.startswith("updated:"):
             sha = message.split(":", 1)[1]
             self._pending_tool_sha = None

tests/test_bundled_updates.py

@@ -300,6 +300,21 @@ class CheckToolUpdateTests(unittest.TestCase):
             self.assertIsNone(check_tool_update())
 
 
+class UpdateDialogDisplayTests(unittest.TestCase):
+    def test_available_version_says_current_when_up_to_date(self):
+        from gui.main import UpdateDialog
+
+        self.assertEqual(UpdateDialog._available_sha_display(None), "Current")
+
+    def test_available_version_shows_pending_sha(self):
+        from gui.main import UpdateDialog
+
+        self.assertEqual(
+            UpdateDialog._available_sha_display("1234567890abcdef"),
+            "12345678",
+        )
+
+
 class AceBundledOnlyTests(unittest.TestCase):
     def _ace_paths(self, base: Path) -> dict:
         offline = base / "offline"