feat(themes): #53 last previews + quarantine neon-glass broken bar

Capture executive-slate + neon-glass preview.png (480x270, theme-shot) —
all 24 themes now have picker previews. Quarantine neon-glass's broken
whole-swap: its waybar.css referenced @accent/@base/… with no
@define-color block, and waybar.nix reads a whole-swap css raw (no palette
prepend), so applying it rendered broken bar colours. Removing it falls
back to the generated bar from the theme's JSON palette.

Verified: V2 theme-shot renders viewed — executive-slate clean; neon-glass
bar now renders correctly, no config-error banner. V0 flake check green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

themes/neon-glass/waybar.css

@@ -1,108 +0,0 @@
-/* Neon Glass Waybar — Segmented floating pills with glassmorphism */
-
-* {
-  font-family: "Inter", "Symbols Nerd Font", sans-serif;
-  font-size: 13px;
-  font-weight: 500;
-  border: none;
-  border-radius: 0;
-  min-height: 0;
-}
-
-window#waybar {
-  /* The main bar background is transparent so the wallpaper shows through */
-  background: transparent;
-  color: @text;
-}
-
-/* 
- * The pill containers: left, center, right.
- * Glassmorphism: semi-transparent base + blur (blur requires hyprland layerrule if waybar doesn't natively blur, but alpha base helps).
- */
-.modules-left,
-.modules-center,
-.modules-right {
-  background: alpha(@base, 0.45);
-  border: 1px solid alpha(@accent, 0.2);
-  border-radius: 20px;
-  margin: 4px 6px;
-  padding: 2px 8px;
-  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
-}
-
-/* Add a glowing top border effect on hover or generally to accent the glass */
-.modules-left {
-  border-top: 1px solid alpha(@accent, 0.6);
-}
-.modules-center {
-  border-top: 1px solid alpha(@text, 0.3);
-}
-.modules-right {
-  border-top: 1px solid alpha(@accentAlt, 0.6);
-}
-
-/* Remove default padding from individual modules so they fit snug in the pill */
-#workspaces button,
-#window,
-#clock,
-#tray,
-#pulseaudio,
-#battery,
-#custom-notification,
-#custom-vpn,
-#custom-powerprofile,
-#custom-updates,
-#custom-doctor {
-  padding: 0 8px;
-  margin: 0 2px;
-}
-
-/* Workspaces */
-#workspaces button {
-  color: @subtext;
-  border-radius: 12px;
-  transition: all 0.2s cubic-bezier(0.25, 1, 0.5, 1);
-}
-
-#workspaces button:hover {
-  background: alpha(@surface, 0.5);
-  color: @text;
-}
-
-#workspaces button.active {
-  color: @accent;
-  background: alpha(@accent, 0.15);
-  box-shadow: 0 0 8px alpha(@accent, 0.4);
-}
-
-#workspaces button.urgent {
-  color: @bad;
-  background: alpha(@bad, 0.15);
-}
-
-/* Indicators */
-#battery.charging { color: @good; }
-#battery.warning:not(.charging) { color: @warn; }
-#battery.critical:not(.charging) {
-  color: @bad;
-  animation: blink 1s steps(2, start) infinite;
-}
-
-#pulseaudio.muted { color: @muted; }
-
-#custom-updates { color: @accentAlt; }
-#custom-doctor { color: @bad; }
-#custom-vpn { color: @accent; }
-
-@keyframes blink {
-  to { color: @text; }
-}
-
-tooltip {
-  background: alpha(@base, 0.85);
-  border: 1px solid alpha(@accent, 0.4);
-  border-radius: 12px;
-}
-tooltip label {
-  color: @text;
-}