gtk(mouse): use "text" enum as default value

Use the .text field of the enum as the default value of the mouse shape
instead of renaming .default. Store the default value as the current
value for use in subsequent commits

src/apprt/gtk/Surface.zig

@@ -424,7 +424,7 @@ pub fn setMouseShape(
     shape: terminal.MouseShape,
 ) !void {
     const name: [:0]const u8 = switch (shape) {
-        .default => "text",
+        .default => "default",
         .help => "help",
         .pointer => "pointer",
         .context_menu => "context-menu",

src/terminal/Terminal.zig

@@ -21,6 +21,7 @@ const Tabstops = @import("Tabstops.zig");
 const trace = @import("tracy").trace;
 const color = @import("color.zig");
 const Screen = @import("Screen.zig");
+const mouse_shape = @import("mouse_shape.zig");
 
 const log = std.log.scoped(.terminal);
 
@@ -84,6 +85,8 @@ previous_char: ?u21 = null,
 /// The modes that this terminal currently has active.
 modes: modes.ModeState = .{},
 
+mouse_shape: mouse_shape.MouseShape = .text,
+
 /// These are just a packed set of flags we may set on the terminal.
 flags: packed struct {
     // This isn't a mode, this is set by OSC 133 using the "A" event.

src/termio/Exec.zig

@@ -1902,7 +1902,7 @@ const StreamHandler = struct {
         self: *StreamHandler,
     ) !void {
         self.terminal.fullReset(self.alloc);
-        try self.setMouseShape(.default);
+        try self.setMouseShape(.text);
     }
 
     pub fn queryKittyKeyboard(self: *StreamHandler) !void {