Architect drift review for the #276 cycle (b048923..HEAD). What holds:
C1 is preserved (the append_write_lock sits at the results-persistence
edge, outside the lock-free sim loop); the mechanism is correct (the
guard spans the full read-counter-then-write critical section in both
locked functions, no re-entrancy via the load paths, poison entered by
into_inner); both fixed paths are pinned by property tests.
One [medium] drift item, resolved here on the fix path: Registry::append
(the flat runs store, runs.jsonl) was the third identical unsynchronized
OpenOptions::append + writeln! path, left standing unguarded beside its
two newly-guarded siblings — and it is public API with external
consumers (C18), so a concurrent caller would hit exactly the #276
corruption. The append_write_lock doc also enumerated the two guarded
stores as if exhaustive. Fixed RED-first: the sibling property test
failed 2/2 against the unguarded path (same "trailing characters"
merged-line corruption), then append takes the same lock and the doc now
names all three JSONL append paths. No other finding: put_blueprint /
put_doc (content-addressed idempotent writes) and TraceStore::write
(per-name whole-file writes) are race-tolerant by shape and correctly
outside the append scope.
Regression gate: no dedicated regression scripts configured; the
project-facts gates all green — cargo test --workspace no failures (the
three concurrency property tests among them), clippy --workspace
--all-targets -D warnings clean, cargo doc --workspace --no-deps clean.
Cycle #276 is drift-clean.
refs #276
claude
98ddcd3595