refactor(core): keep plan prices, cloud quotas and public URLs in one contract (WS-A)

Prices, quotas and site URLs were copied by hand into the edge functions,
admin, desktop and the landing site, and the copies disagreed (Payple billed
9,900/29,900 KRW, admin labels said 12,900/24,900 KRW and $9.9/$19.9, the
site said 2,900/8,900 KRW).

- packages/core/src/plan-catalog.ts is the single source for PLAN_PRICE_KRW
  (Free 0 / Pro 2,900 / Pro+ 8,900 a month) and PLAN_QUOTA.
- packages/core/src/web-urls.ts is the single source for the public origin,
  the /app web-app base path, SITE_URLS and billingUrl().
- Deno cannot bundle packages/core, so scripts/ci/sync-core-contract.mjs
  generates _shared/core-contract.generated.ts; `npm run contract:check`
  fails on drift (same pattern as version:sync).
- Payple checkout, renewal and webhook amount checks now bill the catalog
  price, so existing subscribers move to the new price at their next renewal.
  quota.ts, team-contract.ts and the tests read the generated values.
- Admin MRR/ARR is computed in KRW from the catalog; license labels, the
  release link and desktop PREMIUM_LLM limits derive from core; the site
  imports prices and quotas directly.

Policy: docs/REFACTOR_POLICY.md Wave 3, W3-1 and W3-2.

site/src/pricing.ts

@@ -1,28 +1,23 @@
 // site/src/pricing.ts
-// 요금제 표시 SSOT. 결제 금액의 정본은 서버 결제 카탈로그
-// (server/supabase/functions/_shared/billing-catalog.ts, payple.ts)이며,
-// 여기 값은 그 카탈로그와 같아야 한다. 사용량 한도는
-// packages/core/src/constants.ts의 PREMIUM_MODEL_LIMITS와 같은 값이다.
+// 요금제 카드에 넣을 클라우드 사용량 표시값. 값의 정본은
+// packages/core/src/plan-catalog.ts `PLAN_QUOTA`(서버 quota.ts도 같은 값을 쓴다)이고,
+// 여기서는 i18n 문구의 {haiku}/{sonnet}/{opus} 자리표시자 이름으로 바꾸기만 한다.
+// 가격(PLAN_PRICE_KRW)과 결제 링크(billingUrl)는 Pricing.tsx 가 정본에서 직접 읽는다.
 
-export type PaidTier = 'pro' | 'pro_plus'
+import { PLAN_QUOTA, type PlanQuotaFeature, type PlanTier } from '../../packages/core/src/plan-catalog'
 
-/** 월 요금(원). */
-export const PLAN_PRICE_KRW = {
-  free: 0,
-  pro: 2900,
-  proPlus: 8900,
-} as const
+const QUOTA_PLACEHOLDERS: ReadonlyArray<readonly [placeholder: string, feature: PlanQuotaFeature]> = [
+  ['haiku', 'llm_haiku'],
+  ['sonnet', 'llm_sonnet'],
+  ['opus', 'llm_opus'],
+]
 
-/** 클라우드 다듬기 사용량. -1은 무제한. Free는 주간, 유료는 일간. */
-export const PLAN_CLOUD_QUOTA = {
-  free: { haiku: 250 },
-  pro: { haiku: 1500, sonnet: 300, opus: 50 },
-  proPlus: { haiku: -1, sonnet: 1500, opus: 300 },
-} as const
-
-/** 데스크톱 앱 결제 완료 URL과 같은 웹 결제 페이지. */
-const BILLING_URL = 'https://d3ro.chanpaca.net/billing'
-
-export function billingUrl(tier: PaidTier): string {
-  return `${BILLING_URL}?tier=${tier}`
+/** 클라우드 다듬기 사용량. -1은 무제한. Free는 주간, 유료는 일간. 사용 불가(0) 모델은 뺀다. */
+export function planCloudQuota(tier: PlanTier): Record<string, number> {
+  const quota: Record<string, number> = {}
+  for (const [placeholder, feature] of QUOTA_PLACEHOLDERS) {
+    const { limit } = PLAN_QUOTA[tier][feature]
+    if (limit !== 0) quota[placeholder] = limit
+  }
+  return quota
 }