Rebrand as Playpen.

src/main.zig

@@ -1,4 +1,5 @@
-//! vtabs: a terminal with vertical tabs, built on libghostty-vt.
+//! Playpen: a terminal with vertical tabs, web panes and saved layouts, built
+//! on libghostty-vt.
 //!
 //! libghostty-vt supplies the terminal emulator core (escape sequence
 //! parsing, screen and scrollback state, key/mouse encoding). Everything
@@ -29,7 +30,7 @@ pub fn main() u8 {
     // behavior hands off to an already-running instance over D-Bus, which for
     // a terminal means a second launch silently does nothing visible here and
     // opens a window in whatever session owns the first one.
-    const app = adw.Application.new("dev.greyson.vtabs", .{ .non_unique = true });
+    const app = adw.Application.new("dev.greyson.playpen", .{ .non_unique = true });
     defer app.unref();
 
     _ = gio.Application.signals.activate.connect(app, ?*anyopaque, &onActivate, null, .{});