hyprlock: add config + swap install.sh away from gtklock

Adds hyprlock/hyprlock.conf with Tomorrow Night colors, replaces gtklock
with hyprlock in packages.txt, and updates install.sh to symlink
hyprlock.conf into ~/.config/hypr/ instead of the old gtklock symlinks.

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

packages.txt

@@ -10,7 +10,7 @@ swappy
 wl-clipboard
 brightnessctl
 pamixer
-gtklock
+hyprlock
 swayidle
 ttf-jetbrains-mono-nerd
 polkit-gnome