feat(menu): direct SUPER+CTRL+I / SUPER+CTRL+T binds for System and Tools

BACKLOG #107: both submenus get conflict-free direct bindings through
the canonical keybinds.nix (single source for Hyprland binds and the
SUPER+? cheatsheet) — I follows the Super+I settings muscle memory,
T is Tools. The root-menu rows now show the shortcuts via menuHint.

Verified: V2 — eval audit: 41 binds, no duplicate mods+key; both binds
present in the generated Hyprland config; built nomarchy-menu passes
bash -n with cheatsheet rows + hints rendered. In-session on the live
ISO KVM run: viewed 40-system-menu.png / 41-tools-menu.png in
/tmp/nomarchy-v2-swap-93/ — each bind opens its submenu directly.
V0 flake check green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

modules/home/rofi.nix

@@ -1263,8 +1263,8 @@ ${themeRows}
         choice=$( {
           row "Apps${appsHint}"        applications-all
           row "Look & Feel" preferences-desktop-theme
-          row "Tools"       applications-utilities
-          row "System"      preferences-system
+          row "Tools${menuHint "tools"}"       applications-utilities
+          row "System${menuHint "system"}"      preferences-system
           row "Power${menuHint "power"}"       system-shutdown
           row "Keybindings${menuHint "keybinds"}" preferences-desktop-keyboard
         } | rofi_menu -show-icons -markup-rows -p Menu) || exit 0