## What & why
Signup promo credits. A new logged-out `/promo?code=<code>` landing page
validates the code and carries it through signup via a cookie. When the
new organization is activated by selecting a plan, the code is redeemed
and its credits are applied; the usage page then shows the remaining
promo credits and their expiry.
## Notes
- The code is redeemed at **plan selection**, not org creation: the
credit grant targets the org's usage allowance, which only exists once a
plan is selected — applying at creation would have nothing to grant
onto. Redemption is best-effort and never blocks plan selection.
- Pairs with the corresponding billing-service change (promo code
validate/apply/credits + grant issuance); the two are released together.
## Testing
Verified locally end to end: `/promo` shows the offer, a new account
carries the code through signup, selecting the Free plan redeems it, and
the usage page shows the remaining credits.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Matt Aitken