The master merge rewrote reconcileInstructionContext and dropped this
branch's gate: when no transition survives rendering (tiny budgets
produce notice-only text), emit nothing and commit nothing so the next
pass retries. Restore it, align the inbox one-byte test with that
contract (an unrepresentable change is held back, not committed at 1
byte), and move the nested-retry test's probe assertions to sync time
where reconciliation now runs. Also restore master's markdown spec
casts lost in an earlier merge.
ZiyaZhang
fe2703b641