Implement server management enhancements with window close handling

- Introduced a checkbox in the ConnectionForm to allow users to keep the server running when the app closes.
- Added a setupWindowCloseHandler function to manage server shutdown based on user preference.
- Updated App component to integrate the new window close handling logic.
- Created a reusable Checkbox component for better UI consistency.
- Modified serverStore to include state management for the new setting.

app/src/stores/serverStore.ts

@@ -10,6 +10,9 @@ interface ServerStore {
 
   mode: 'local' | 'remote';
   setMode: (mode: 'local' | 'remote') => void;
+
+  keepServerRunningOnClose: boolean;
+  setKeepServerRunningOnClose: (keepRunning: boolean) => void;
 }
 
 export const useServerStore = create<ServerStore>()(
@@ -23,6 +26,10 @@ export const useServerStore = create<ServerStore>()(
 
       mode: 'local',
       setMode: (mode) => set({ mode }),
+
+      keepServerRunningOnClose: false,
+      setKeepServerRunningOnClose: (keepRunning) =>
+        set({ keepServerRunningOnClose: keepRunning }),
     }),
     {
       name: 'voicebox-server',