Planner tasks from notes should update the notes page that they link
to while maintaining the special links. This means that
planner-jump-to-linked-task needs to be smarter.
Let us look at case 1: Link to plan page note
The plan page has a date link, no anchor. The date page has a plan
link with an anchor. Example:
#A1 _ Foo (2004.03.11)
#A1 _ Foo ([[SomePage#1][SomePage]])
Problem! The plan page does not contain enough information to
reconstruct the link if necessary. I can’t think of a neat way to fix
this yet. Can anyone?