Two correctness fixes that gate enabling the coupon test:
1. On-the-fly pricing. The coupon block hardcoded '$79 $47' (only true at 40%
off) — a false claim on the 20/30% arms. Now build_trucking_campaigns.py
reads api/src/service-catalog.ts (same source checkout uses) and computes
coupon_price_full / coupon_price_deal per recipient as full - round(full*pct/100),
exactly matching the server. Service-fee-only; non-discountable services
(boc3-filing passthrough) get NO price and fall back to percent-only copy.
Quotes the service the email is ABOUT (mcs150 $79, reactivation $149), not the
bundle the CTA happens to link to. service-catalog.ts now ships in the worker
image; helper degrades to percent-only if it can't be read.
2. CTA URL bug (likely a big driver of the zero-click problem). Main campaign
CTAs render '/order/slug&utm_source=...' (no '?') -> HTTP 404, verified live.
Deficiency CTAs would double-'?' once a coupon added '?code='. lp_link now
owns the query (?dot=...&code=...) so every template appends with a leading
'&' and is valid in all 4 states (main/deficiency x coupon on/off), verified
against live URLs returning 200.
Deficiency _deal_box now shows real was/now prices (percent-only for boc3).
Tests: 7/7 pass (adds URL-wellformed + price-matches-checkout cases).
