fix(lint): don't hide same-stem orphans behind qualified links

[jichaowang02-lang]

Summary

find_orphans builds the set of linked pages by adding, for every wikilink, both its full path and its bare stem:

for lnk in links:
    incoming.add(lnk.strip().strip("/"))
for lnk in links:
    incoming.add(Path(lnk.strip()).stem)   # stem of EVERY link, even qualified ones

So a qualified link like [[concepts/foo]] also registers the bare stem foo. Any other page that merely shares that stem in a different directory — e.g. summaries/foo — is then treated as "linked" (stem in incoming) and excluded from orphan detection. A genuine orphan is silently missed.

Fix

Only register the bare stem when the link itself is a bare stem (no /). Qualified links register only their full path:

cleaned = lnk.strip().strip("/")
incoming.add(cleaned)
if "/" not in cleaned:
    incoming.add(Path(cleaned).stem)

Bare [[foo]] links still resolve by stem (a page named foo in any directory stays non-orphaned), so the intended bare-link behaviour is preserved.

Testing

$ pytest tests/test_lint.py::TestFindOrphans -q
6 passed

• test_qualified_link_does_not_hide_same_stem_orphan — summaries/dup is now flagged when only [[concepts/dup]] is linked (fails before the fix).
• test_bare_stem_link_still_matches_same_stem_page — a bare [[dup]] link still marks a same-stem page as non-orphan.

(The 4 unrelated TestFindMissingEntriesRegistry failures are pre-existing on main and untouched by this change.)

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[KylinMountain]

LGTM. Thanks for the sharp catch and the clean fix! Much appreciated 🙏