Hyprland: float HDT overlay

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

settings/hyprland.nix

@@ -378,6 +378,23 @@ in
               workspace = "special silent",
             })
 
+            -- Hearthstone Deck Tracker's overlay: a transparent WPF window HDT
+            -- itself keeps moved and sized over Hearthstone (title from its
+            -- OverlayWindow XAML). The generic tile rule above would tile it
+            -- like a game; float it bare and never hand it focus.
+            hl.window_rule({
+              name  = "hdt-overlay",
+              match = { class = "^steam_app_(0|default)$", title = "^HearthstoneOverlay$" },
+              float = true,
+              no_initial_focus = true,
+              decorate = false,
+              border_size = 0,
+              no_shadow = true,
+              no_blur = true,
+              no_dim = true,
+              no_anim = true,
+            })
+
             -- Spotify lives on a special workspace for its whole session;
             -- SUPER+M slides it in and out. Matched on class, not title: the
             -- title carries the current track.