Gifting & small-team seat purchases

Why / Context

PRD §7.2E: corporate gifting / small-team seat purchase is a lightweight revenue lever distinct from the full enterprise motion — a manager buying 5 seats of a course for their team shouldn't need a sales call. Gift columns were built into OrderItem at MVP; this issue turns them on.

Schema already in place — NO migration required

• OrderItem.giftRecipientEmail / giftClaimToken (unique) / giftClaimedById / giftClaimedAt
• CartItem.giftRecipientEmail + metadata (gift message)
• Enrollment(source: GIFT)
• Quantity >1 on OrderItem supports seat-pack purchases; Waitlist not needed here

Implementation plan

1. Gift purchase flow: "Buy as gift" on course/project pages → recipient email + message at cart line level → checkout normally; fulfillment mints giftClaimToken per unit instead of enrolling the buyer.
2. Claim flow: recipient email w/ claim link → signup/login → claim page validates token (unclaimed, unexpired per policy) → creates Enrollment/ProjectInstance(source GIFT) → token consumed (giftClaimedById/At).
3. Buyer management: /account/gifts — status per gift (sent/claimed), resend email, reassign recipient before claim, cancel-unclaimed within refund window (normal Refund path).
4. Team seats (multi-quantity): quantity picker for eligible items → N claim tokens under one OrderItem → buyer's seat-management table (invite emails per seat, revoke unclaimed, claim links) — deliberately no org/license machinery (that's enterprise).
5. Pricing: optional volume discount rule in pricing engine (PlatformConfig thresholds, e.g., 5+ seats −10%).
6. Emails: gift-received (with message), reminder before expiry, claimed-notification to buyer (via notification facade).
7. Edge cases: recipient already enrolled → credit-to-account choice (support flow documented); refunds void unclaimed tokens.
8. GST note: B2B buyers can enter GSTIN in billTo (field exists) — invoice shows it (full B2B treatment in issue #24).

Acceptance criteria

• Gifted course reaches recipient; claim creates their enrollment; buyer never gets access
• 5-seat purchase yields 5 claim links; buyer can invite/revoke unclaimed seats
• Refund of an unclaimed gift voids its token; claimed gifts follow normal consumption guards
• Volume discount applies at configured thresholds
• Duplicate-claim and expired-token paths handled gracefully

Dependencies / sequencing

• MVP M7 fulfillment is the base; notification facade (issue #10) optional

Start with MVP M7 fulfillment and the existing OrderItem gift fields, Enrollment(source: GIFT), and CartItem gift metadata. Trace checkout, claim, account gift management, refund, pricing, and notification-facade entry points, then verify the acceptance criteria for per-seat tokens, claiming, refunds, discounts, and duplicate or expired tokens.