How to know if a page contains a tag separately from its tasks?

[ces3001]

I’d like to know if the page itself has been tagged with a particular tag, or only one of the tasks within it has that tag.

In other words, if querying for #test, I’d like

1. All tasks, regardless of how they are tagged, from a page tagged with #test (that is, that tag appears separate from all tasks), OR
2. Any task tagged with #test, and if the page itself is not tagged, then, only those tasks.

I can’t figure out how to determine if a page is tagged (and none of the tasks in it are tagged), or if the tag is on a task.

Any help is appreciated

[igrepstuff]

TASK FROM ""
WHERE contains(file.tags, "#tag")
GROUP BY file.link AS filename
SORT filename.file.mtime DESC