#23 · Reputation decay: weekly cron drops idle reputation by 1%

Context

Reputation should reflect recent activity, not lifetime hoarding. A small weekly decay (1% of reputation if user had no activity that week) keeps the leaderboard fresh and aligned with the scoreboard's existing weekly/monthly periods.

Acceptance criteria

• [ ] Sunday 04:00 UTC cron iterates all users, applies 1% decay if 0 actions in last 7 days
• [ ] Decay logged as a reputation_decay event for transparency
• [ ] Floor: never decay below 100 reputation (or whatever the starting value is)
• [ ] Admin can disable per user (reputation_decay_eligible=0)

Technical hints

• Mirror scoreboard's cron pattern: [triggers] crons = ["0 4 * * 0"] in wrangler.toml
• Single transactional UPDATE — DON'T iterate row-by-row
• Store policy floor in apps/task-exchange/src/config.ts not hardcoded

--- *Submit a merge request that says Closes #<this issue iid> in the description. On merge to main, the GitLab webhook will auto-award your bounty + the standard merge_pr (40 pts) to your scoreboard account. Email on commit must match your Authentik email.*