feat(db): profile service discounts and Stripe catalog on services

[achneerov]

Closes #42

Overview

Extends the services table with optional Stripe catalog identifiers (stripe_product_id, stripe_default_price_id) so each offering can be tied to a Product and default Price in Stripe.

Adds profile_service_discounts for per-user, per-service admin-granted discounts: stores the Stripe coupon id, optional max_uses, use_count, optional expires_at, and enforces at most one row per user and service. Checkout and subscriptions should apply this coupon alongside line items that use the service’s price.

This uses a coupon-based model instead of storing alternate Stripe price ids per user, which keeps catalog pricing clear and aligns with how Stripe applies discounts.

Testing

Schema-only change. Apply locally with pnpm db:push or generate a migration with pnpm db:generate when you are ready to version database changes.

Screenshots / Screencasts

N/A — no UI changes.

Checklist

• Code is neat, readable, and works
• Issue number is linked
• Branch is linked

Notes

Issue #42 originally described a services_pricing_mapping table with per-user stripe_price_id; this PR implements the same product goal with Stripe coupons plus optional use limits, which fits one-time and subscription flows without replacing catalog prices.

[RenaudBernier]

Looks good. Thank you for implementing these changes and making the script.