Wave-6 review (Teacher stream): the injection runner's null-embedder
branch failed with 'graph.embeddingModel is null', but the resolver
collapses BOTH an unset model AND a set model whose provider key
vanished into null — a key race mid-session would have reported a
false 'null' setting. The message now names both causes honestly.
Pinned by a new failure-mode test (null resolver → honest error, never
a phantom query).
Review verdicts (no changes needed): the session-deletion guard sits at
every chat-merge boundary (per batch, fresh lookup, rides the existing
AbortError path — nothing merged, nothing checkpointed, registry
cleaned in the finally); persistRunUsage's deleted-chat skip composes
with appendSourceUsage's vanished-source no-op so no usage record
dangles; notes sources have no deletion surface so the notes path needs
no guard. The embedding tail's non-fatal contract holds (failure →
recordEmbedFailure → no stage, extractor/auditor usage still persists
through the catch).
amosblomqvist
d755ae82b7