feat(web): add keyboard shortcuts for tool navigation

Register global keyboard shortcuts: Cmd/Ctrl+K to focus search,
Cmd/Ctrl+/ for tools view, Cmd/Ctrl+Shift+D to toggle theme,
Cmd/Ctrl+Alt+1-8 for quick tool navigation. Uses platform-aware
mod key detection (Cmd on Mac, Ctrl on Windows/Linux).

apps/web/src/components/common/keyboard-shortcut-provider.tsx

@@ -0,0 +1,15 @@
+import { useKeyboardShortcuts } from "@/hooks/use-keyboard-shortcuts";
+
+/**
+ * Wrapper that registers global keyboard shortcuts.
+ * Must be rendered inside a <BrowserRouter> so that
+ * useNavigate() works inside the hook.
+ */
+export function KeyboardShortcutProvider({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  useKeyboardShortcuts();
+  return <>{children}</>;
+}