feat(config): enable selective blur for terminals and set flat decoration defaults

dot_config/kitty/kitty.conf

@@ -4,15 +4,14 @@ bold_italic_font auto
 window_padding_width 8
 hide_window_decorations yes
 # Transparency: kitty's own alpha, not the compositor's -- Hyprland fades a
-# window uniformly (chrome included), kitty only makes the cell background
-# translucent, so text stays fully opaque on top of it.
+# whole window (chrome included), kitty only makes the cell background
+# translucent, so text stays fully opaque on top of it. This alpha is also what
+# makes kitty the one window Hyprland blurs: hypr/looknfeel.lua enables blur
+# globally and then opts every window out except the terminal classes, and an
+# opaque window has no backdrop to blur. kitty's own `background_blur` does
+# nothing here -- it rides ext-background-effect-v1, which Hyprland ignores
+# while decoration:blur:enabled is false, and is redundant once it is true.
 background_opacity 0.9
-# Per-window blur without global blur. Hyprland 0.56 implements the staging
-# protocol ext-background-effect-v1 and kitty's Wayland backend speaks it, so
-# kitty asks the compositor to blur the region behind its own surface. That is
-# why hypr/looknfeel.lua can keep decoration:blur:enabled = false: nothing else
-# on screen pays for the blur pass. Needs background_opacity < 1.
-background_blur 1
 cursor_blink_interval 1
 copy_on_select auto
 strip_trailing_spaces smart