fix(previewer): Apply fn_transform_cmd to regex query parsing

Author: drop-stones

lua/fzf-lua/previewer/builtin.lua

@@ -1040,7 +1040,10 @@ function Previewer.buffer_or_file:set_cursor_hl(entry)
   local mgrep, glob_args = require("fzf-lua.providers.grep"), nil
   local regex = self.opts.__ACT_TO == mgrep.grep and self.opts._last_query
       or self.opts.__ACT_TO == mgrep.live_grep and self.opts.search or nil
-  if regex and self.opts.rg_glob and self.opts.glob_separator then
+  if regex and self.opts.fn_transform_cmd then
+    local _, query = self.opts.fn_transform_cmd(regex, self.opts.cmd, self.opts)
+    regex = query or regex
+  elseif regex and self.opts.rg_glob and self.opts.glob_separator then
     regex, glob_args = require("fzf-lua.make_entry").glob_parse(regex, self.opts)
   end
   if regex then