Redesign launcher: modern dark UI, 4-col grid, pill filters, footer

- 640x490 window, larger cards (132x106), 4 columns
- Full-width search bar in header with active-state indicator
- Category filters as pill chips with gaps
- Cards show surface bg + accent top bar on hover
- Footer bar with app count and keyboard hints
- Fix menu: pavucontrol -> alsamixer in xterm

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

wm/src/menu.c

@@ -12,7 +12,7 @@ static const MenuItem MENU_ITEMS[] = {
     { "──────────────────", NULL                                           },
     { "Web Browser",       "firefox &"                                    },
     { "System Monitor",    "xterm -T 'System Monitor' -e htop &"          },
-    { "Volume Control",    "pavucontrol &"                                },
+    { "Volume Control",    "xterm -e alsamixer &"                           },
     { "Software Updates",  "orionpkg &"                                   },
     { "Display Settings",  "arandr &"                                     },
     { "──────────────────", NULL                                           },