feat: add quit button

gallery/tui.py

@@ -158,6 +158,7 @@ class GalleryTUI(App):
     BINDINGS = [
         Binding("ctrl+s", "save_config", "Save Config"),
         Binding("ctrl+S", "save_config", show=False),  # Ctrl+Shift+S alias
+        Binding("ctrl+q", "quit", "Quit"),
     ]
 
     # reactive is a Textual descriptor.  When `dirty` changes value, Textual
@@ -240,6 +241,7 @@ class GalleryTUI(App):
             yield Static("", id="dirty-indicator")
             yield Button("Save Config", id="save-btn",     variant="success")
             yield Button("Generate",    id="generate-btn", variant="primary")
+            yield Button("Quit",        id="quit-btn",     variant="error")
 
         yield Footer()
 
@@ -321,6 +323,10 @@ class GalleryTUI(App):
     def action_save_config(self) -> None:
         self._save_config()
 
+    @on(Button.Pressed, "#quit-btn")
+    def action_quit(self) -> None:
+        self.exit()
+
     @on(Button.Pressed, "#save-btn")
     def _save_config(self) -> None:
         """Write all field values back to the config file via ConfigManager.