feat: add general assist feature and enhance shortcut management

- Introduced a new "General Assist" shortcut, allowing users to open SurfSense from anywhere.
- Updated shortcut management to include the new general assist functionality in both the desktop and web applications.
- Enhanced the UI to reflect changes in shortcut labels and descriptions for better clarity.
- Improved the Electron API to support the new shortcut configuration.

surfsense_desktop/src/modules/shortcuts.ts

@@ -1,9 +1,11 @@
 export interface ShortcutConfig {
+  generalAssist: string;
   quickAsk: string;
   autocomplete: string;
 }
 
 const DEFAULTS: ShortcutConfig = {
+  generalAssist: 'CommandOrControl+Shift+S',
   quickAsk: 'CommandOrControl+Alt+S',
   autocomplete: 'CommandOrControl+Shift+Space',
 };