feat: replace loupe with imv and update plymouth theme

- Replaced Loupe with imv for a keyboard-driven image viewer experience.

- Updated Plymouth logo with Firewatch-inspired ASCII art gradient.

- Updated Plymouth background color to match Firewatch palette (#2D112A).

apps/plymouth/themes/hakase/hakase.script

@@ -1,7 +1,7 @@
 # Omarchy Plymouth Theme Script
 
-Window.SetBackgroundTopColor(0.101, 0.105, 0.149);
-Window.SetBackgroundBottomColor(0.101, 0.105,  0.149);
+Window.SetBackgroundTopColor(0.176, 0.067, 0.165);
+Window.SetBackgroundBottomColor(0.176, 0.067,  0.165);
 
 logo.image = Image("logo.png");
 logo.sprite = Sprite(logo.image);