#293 Award leaderboard points for referrals and collective invites

Problem

The leaderboard currently rewards activity inside swamp.club (publishing extensions, contributions, etc.) but doesn't reward operatives who grow the community. Word-of-mouth and collective recruitment are some of the highest-leverage growth signals, and right now there's no incentive — or even tracking — for an operative who brings new people in.

Proposed solution

Award leaderboard points when an operative is responsible for a new operative joining swamp.club. Two trigger paths:

1. Direct referral link — operatives get a personal referral URL (e.g. /?ref={username}). When a new operative signs up via that link, the referrer is credited.
2. Collective invite accepted — when an operative invites someone to a collective and that invitee accepts and creates an account, the inviter is credited.

Three reward shapes worth considering (not mutually exclusive):

• Points on signup — flat award the moment the referred operative completes signup. Simple, immediate feedback, but cheap to game.
• Points on milestone — referrer gets points only when the referred operative reaches a meaningful milestone (e.g. tier-up, first extension push, first workflow run). Higher-quality signal, harder to farm.
• Mutual kickoff bonus — referee also gets a small starting bonus, both to thank them for showing up and to reduce the cold-start gap on the leaderboard.

A combined approach (small signup award + larger milestone award + small referee bonus) likely captures the most value.

Considerations

• Anti-abuse — needs guardrails so a single operative can't farm signups. At minimum: cap referral points per period, require email verification, and probably weight by the referee's actual activity (milestone-based award helps here).
• Attribution model — how is the referrer recorded? Cookie on click + persisted on account creation is the standard pattern. Collective-invite path is cleaner — the inviter is already known.
• Leaderboard visibility — should referral points be a separate score category, or roll into the main leaderboard? A separate "recruiter" badge or sub-leaderboard might surface community builders without distorting the main extension/contribution rankings.
• Self-referral / circular invites — block referrals between accounts that share infrastructure (same email domain in some cases, same IP within a window, etc.).

Alternatives considered

• Badges only, no points — award a "recruiter" badge tier instead of leaderboard points. Lower stakes, but also lower incentive.
• Collective-only — restrict the mechanic to collective invites and skip the public referral link. Simpler attribution, but misses the broader top-of-funnel.
• Do nothing — rely on organic growth. Cheapest, but leaves a clear motivator on the table.