Massively Reduce Repo Code with DBOS

Identify an opportunity to massively reduce the amount of code (lines of code) in any part of the repo: - Similar functionality that can be unified and reused - Code that has been valuable but no more - Front end component or group of them duplicates another component functionality. Use the most modern and nice looking - Move to DBOS and get rid of supporting functionality relying on DBOS - etc. Implement it

Recon found no large safe cut (durable flows already on DBOS, no dead modules). Merged #5348: Tasks.tsx row writes onto useBusyIds + one preemptForecast helper, −33 lines net, behaviour-neutral. Full gate green, dev deploy succeeded. Follow-ups in report.