feat: centralize theme palette + add waybar bluetooth module

Theme centralization:
- theme/colors.json is now the single source of truth for the palette.
- New theme/generate-theme.py renders, at install time, the three derived
  artifacts into ~/.config: colors.css (waybar/wofi @import), mako config,
  and hyprlock-colors.conf (hyprlang $tn_* variables).
- theme/colors.css removed from the repo (now generated); install.sh calls
  the generator instead of the old inline mako snippet.
- hyprlock.conf sources the generated color file and uses $tn_* variables
  instead of hardcoded rgba() values.
- Generator covered by theme/test_generate_theme.py.

Bluetooth:
- Added waybar built-in bluetooth module (config.jsonc + style.css), with
  bluez/bluez-utils in packages.txt.

Includes design spec and implementation plan under docs/superpowers/.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

waybar/style.css

@@ -56,3 +56,15 @@ window#waybar {
 #temperature.critical {
   color: @tn-red;
 }
+
+#bluetooth {
+  padding: 0 12px;
+}
+
+#bluetooth.connected {
+  color: @tn-blue;
+}
+
+#bluetooth.disabled, #bluetooth.off {
+  color: @tn-fg-muted;
+}