Previous setStatus() did read-modify-write:
findOne → if-exists save / else create+save
Two concurrent first-time writes for the same userId both saw no row,
both INSERT'd, second hit unique-key (agent_presences.PRIMARY) and 500'd
with "Duplicate entry '<userId>' for key 'agent_presences.PRIMARY'" —
visible in prod (2026-05-25 23:23:35Z) when Fabric.OpenclawPlugin's
presence-sync emitted two PUTs ~10 ms apart for the same agent (its
tick-overlap is being fixed separately in nav/Fabric.OpenclawPlugin).
Replace with repo.upsert(values, ['userId']) — compiles to MySQL
`INSERT … ON DUPLICATE KEY UPDATE`, atomic at the storage engine,
no read needed, no race window. Synthesize the returned entity from
the values we just wrote rather than a SELECT round-trip; controller
only reads {userId, status} off it.
Sim verified with 5 parallel PUTs to a fresh userId: all 200, no
Duplicate errors in guild log (was: 1 × 200 + 4 × 500 with the
old code).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
