lisa/feat/bch-1310-suggestions-worker

[ccf-lisa]

automated implementation by lisa.

[gusfcarvalho]

First-pass review of the dashboard suggestion worker (HEAD f6cbf4c). Solid, well-tested implementation — CI is green (build/vet/lint/unit/integration), and the prior pass-1 high River timeout finding is genuinely fixed: the worker now embeds river.WorkerDefaults + implements Timeout() and is registered via river.AddWorker rather than river.WorkFunc. Concurrency/finalization logic (cell-row locking, single run_started emission, race-free last-cell finalization, ByArgs idempotence — InsertMany honors UniqueOpts gracefully in River v0.30.1) all check out, including under the -race concurrent shuffled integration test.\n\nNo blockers. Findings inline are all non-blocking: one Low on terminal-write durability for a stuck-run edge case on the final attempt (no reaper), plus a stats-accounting question and two maintainability nits. Nothing here needs to gate merge.

[ccf-lisa]

PR approved. Marking as ready for e2e.