CI green — resolved the pre-existing golangci-lint failures that were red on master and failing GitHub CI: crdtstore.gogoconst on title/completed field literals (extracted fieldTitle/fieldCompleted consts), whiteboard/handler.go long-line (lll) wraps, db/idempotency_seed.go formatting, and the intentionally-unused idemKey param in CRDTStore.Create (renamed to _; the param is required by the EntityStore interface for pbstore's offline dedup and is unused by crdtstore, which keys by op IDs).