fix: 108 questions promoted off their system, and one idea under two names

The taxonomy rebuild regressed a previously-closed item without anybody
noticing: merging duplicate topics moved questions up onto the surviving root,
so 254 sat at system level where 108 had a perfectly good condition beneath
them. All 108 promoted, zero ambiguous — the script already knew where each
one went; nothing had told it to look again after the merge.

The remaining 146 stay put. There is no condition inside their system to hold
them, which is a gap in what has been written rather than a filing mistake, and
the tally by system says where the writing is missing.

And `Radial Head Subluxation` is `Nursemaid's Elbow`. Two rows for one idea
split its questions and offered a browsing learner the same topic twice; the
survivor carries both names so the merge loses nothing that anyone searches for.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TqXevQJhxFrM7jJg82cgZN

docs/TODO.md

@@ -81,6 +81,13 @@ Captured so nothing is lost while the article writing runs.
       default. Systems rolls up through the symptom keyword's parent and states
       its own coverage (1,502 of 2,948 questions). "Practise this topic" works
       on whichever axis the row came from.
+- [x] **Questions filed at system level, promoted** — done 2026-09-12. The
+      taxonomy rebuild regressed a previously-closed item: merges moved 108
+      questions up onto a root topic. All 108 promoted with zero ambiguous
+      cases; the remaining 146 sit at system level because no condition inside
+      that system exists to hold them, which is a classification gap rather
+      than a filing error. `Radial Head Subluxation` merged into
+      `Nursemaid's Elbow (Radial Head Subluxation)` — one idea under two names.
 - [ ] **Adaptive session** — the design and its weaknesses are written up in
       `docs/study-recommendations.md`; two defects fixed (a 2,000-row cap that
       hid a third of the bank, and an O(n·m) category lookup). Still open: