Fetch OpenCode Go's catalog as the settings window opens

Codex already refreshes its boxes from the source at open, so the
built-in list is never the whole truth for longer than a window takes to
build. OpenCode Go now gets the same courtesy: one request to /models on
a background thread, both of its boxes refilled with the picked model
kept, skipped entirely when there is no key to send.

tests/test_ui.py

@@ -135,6 +135,8 @@ class Settings(DikteTest):
                                             "_load_transcribe_models"))
         self.enterContext(mock.patch.object(settings_ui.SettingsWindow,
                                             "_load_codex_models"))
+        self.enterContext(mock.patch.object(settings_ui.SettingsWindow,
+                                            "_load_opencode_models"))
         # The local model boxes fetch their own list the moment they are shown,
         # from a thread, which is nobody's test failing but a real request.
         self.enterContext(mock.patch.object(settings_ui.LocalModelBox,
@@ -285,6 +287,20 @@ class Settings(DikteTest):
         self.assertEqual(window.cleanup_codex_model.currentText(),
                          "my-own-model")
 
+    def test_opencode_answering_refills_both_of_its_boxes(self):
+        """The catalog fetched at open replaces the built-in list in the
+        cleanup and agent boxes alike, and neither loses what was picked."""
+        conf = self.config(cleanup_opencode_model="my-own-model")
+        window = self.window(conf)
+        window._on_opencode_models_loaded(["glm-9", "kimi-k9"])
+        for combo in (window.cleanup_opencode_model,
+                      window.assistant_opencode_model):
+            with self.subTest(combo=combo.objectName() or "combo"):
+                offered = [combo.itemText(i) for i in range(combo.count())]
+                self.assertEqual(offered, ["glm-9", "kimi-k9"])
+        self.assertEqual(window.cleanup_opencode_model.currentText(),
+                         "my-own-model")
+
     def test_a_fetched_opencode_list_lands_in_opencode_s_own_box(self):
         """The OpenRouter and meeting boxes are not refilled by another
         provider's catalog, and the picked model survives the refill."""
@@ -1026,7 +1042,9 @@ class MeetingSources(DikteTest):
                 mock.patch.object(settings_ui.SettingsWindow,
                                   "_load_transcribe_models"), \
                 mock.patch.object(settings_ui.SettingsWindow,
-                                  "_load_codex_models"):
+                                  "_load_codex_models"), \
+                mock.patch.object(settings_ui.SettingsWindow,
+                                  "_load_opencode_models"):
             window = settings_ui.SettingsWindow(cfg.Config())
         self.addCleanup(window.deleteLater)
         self.addCleanup(window.close)
@@ -1058,6 +1076,8 @@ class LocalModels(DikteTest):
         # And one with Codex on it would ask it for its model list.
         self.enterContext(mock.patch.object(settings_ui.SettingsWindow,
                                             "_load_codex_models"))
+        self.enterContext(mock.patch.object(settings_ui.SettingsWindow,
+                                            "_load_opencode_models"))
 
     def window(self, conf):
         window = settings_ui.SettingsWindow(conf)