feat(config): add Ghostty window grouping configuration

dot_config/hypr/hyprland.lua

@@ -68,6 +68,12 @@ o.window([[^com\.anthropic\.Claude$]], { workspace = "special:claude silent" })
 o.window([[^com\.fastmail\.Fastmail$]], { workspace = "special:fastmail silent" })
 o.window([[^Beeper$]], { workspace = "special:beeper silent" })
 
+-- Ghostty opens as a group (tabbed, groupbar on top). Each Ghostty window is
+-- its own tmux session (~/.local/bin/ghostty-tmux) titled with the session
+-- name, so the groupbar reads as a session list; with group.auto_group, more
+-- Ghostty windows opened from it join the same group.
+o.window([[^com\.mitchellh\.ghostty$]], { group = "set" })
+
 -- SUPER + CTRL + ALT + Y / SUPER + SHIFT + Y: the YouTube web app, summoned
 -- by ~/.local/bin/omarchy-summon. Not a scratch workspace: a floating,
 -- pinned window parked in the bottom-left corner at 30% of the monitor on