twait in ms (multiples of the FEL period), fixed tmove kept in the parameters

- mode 7 uses tmove/twait in ms like mode 5 (shapepath divides by fel_per,
  its 'shots' doc is wrong): tmove is fel_per for both (was 1 for mode 7)
- wait field in ms, steps of fel_per, typed values snapped to a multiple
- the panel writes the fixed tmove into the parameter text, add obj and
  update param set it too (fix_motion_param), so it shows in the object
  information; the collection still enforces it
- warning when the text has another tmove or a twait that is not a
  multiple of it; a saved text gets the fixed tmove at startup

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

ModuleFixTarget.py

@@ -276,7 +276,7 @@ class WndFixTarget(QWidget):
       else:
         grp=wnd._goTracked
         go=grp.childItems()[path[0]]
-        go._param=self.get_param()
+        go._param=wnd.fix_motion_param(self.get_param())
         data=grp.childItems()
         self._tree.setData(data)