fix: continue question selection after graph updates

docs/v0.7-question-simplicity-experiment.md

@@ -1,3 +1,28 @@
+## Post-update selection invariant
+
+After every successful graph update, the full deterministic question-selection pipeline must run again whenever eligible unresolved unknowns remain.
+
+That means the update path must not stop at graph mutation, child resolution, emergent unknown creation, decomposition, or upward propagation. It must continue through:
+
+```text
+updated graph
+→ rebuild reasoning state
+→ identify unresolved candidates
+→ select active unknown
+→ atomicity assessment
+→ answerability assessment
+→ decompose if required
+→ reselect
+→ reasoning-pattern selection
+→ investigation-strategy selection
+→ question-family selection
+→ question formulation
+→ complexity validation
+→ selectedQuestion
+```
+
+Returning no question is only valid when no eligible unresolved candidate remains, the case is complete, ambiguity cannot be safely resolved, or question formulation fails validation with an explicit deterministic reason.
+
 # v0.7 Question Simplicity Experiment
 
 ## Observed failure