feat(ui-ext): make 'mousehide' into proper ui_option (#25532)

src/nvim/option_vars.h

@@ -571,6 +571,7 @@ EXTERN char *p_mouse;           ///< 'mouse'
 EXTERN char *p_mousem;          ///< 'mousemodel'
 EXTERN int p_mousemev;          ///< 'mousemoveevent'
 EXTERN int p_mousef;            ///< 'mousefocus'
+EXTERN int p_mh;                ///< 'mousehide'
 EXTERN char *p_mousescroll;     ///< 'mousescroll'
 EXTERN OptInt p_mousescroll_vert INIT(= MOUSESCROLL_VERT_DFLT);
 EXTERN OptInt p_mousescroll_hor INIT(= MOUSESCROLL_HOR_DFLT);

src/nvim/options.lua

@@ -5452,9 +5452,11 @@ return {
       ]=],
       enable_if = false,
       full_name = 'mousehide',
+      redraw = { 'ui_option' },
       scope = { 'global' },
       short_desc = N_('hide mouse pointer while typing'),
       type = 'bool',
+      varname = 'p_mh',
     },
     {
       abbreviation = 'mousem',