feat: enhance KanbanPageClient and KeyboardShortcuts with new functionality

- Added `toggleFontSize` and `handleToggleDueDateFilter` to `KanbanPageClient` for improved user control over font size and due date visibility.
- Replaced `useKeyboardShortcuts` with `useGlobalKeyboardShortcuts` for better shortcut management across components.
- Updated keyboard shortcuts in `KeyboardShortcutsContext` to include new actions for toggling objectives, due date filters, and font size.
- Refined `KeyboardShortcutsModal` layout for better usability and consistency.
- Removed deprecated `useKeyboardShortcuts` hook to streamline codebase.

src/components/KeyboardShortcuts.tsx

@@ -1,11 +1,11 @@
 'use client';
 
-import { useKeyboardShortcuts } from '@/hooks/useKeyboardShortcuts';
+import { useGlobalKeyboardShortcuts } from '@/hooks/useGlobalKeyboardShortcuts';
 import { useKeyboardShortcutsModal } from '@/contexts/KeyboardShortcutsContext';
 import { KeyboardShortcutsModal } from '@/components/ui/KeyboardShortcutsModal';
 
 export function KeyboardShortcuts() {
-  useKeyboardShortcuts();
+  useGlobalKeyboardShortcuts();
   const { isOpen, shortcuts, closeModal } = useKeyboardShortcutsModal();
   
   return (