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.

server/supabase/functions/_shared/quota.ts

@@ -3,64 +3,25 @@
 // Free=Haiku 250/주간, Pro=모델별 일간, Pro+=Haiku 무제한
 
 import { createClient } from '@supabase/supabase-js'
+import {
+  PLAN_QUOTA,
+  type PlanQuota,
+  type PlanQuotaFeature,
+  type PlanQuotaPeriod,
+  type PlanQuotaTier,
+} from './core-contract.generated.ts'
 
-export type Tier = 'free' | 'pro' | 'pro_plus' | 'team' | 'enterprise'
+export type Tier = PlanQuotaTier
 
 /** 쿼터 추적 키 — 모델별 분리 */
-export type QuotaFeature =
-  | 'stt_transcribe'
-  | 'llm_haiku'
-  | 'llm_sonnet'
-  | 'llm_opus'
-  | 'realtime_session'
+export type QuotaFeature = PlanQuotaFeature
 
-export type QuotaPeriod = 'daily' | 'weekly'
+export type QuotaPeriod = PlanQuotaPeriod
 
-interface ModelQuota {
-  /** -1=무제한, 0=사용불가, 양수=한도 */
-  limit: number
-  period: QuotaPeriod
-}
+type ModelQuota = PlanQuota
 
-/** 모델별 쿼터 정책 */
-const MODEL_QUOTA: Record<Tier, Record<QuotaFeature, ModelQuota>> = {
-  free: {
-    stt_transcribe: { limit: 250, period: 'weekly' },
-    llm_haiku: { limit: 250, period: 'weekly' },
-    llm_sonnet: { limit: 0, period: 'daily' },   // 사용불가
-    llm_opus: { limit: 0, period: 'daily' },      // 사용불가
-    realtime_session: { limit: 0, period: 'daily' }, // 사용불가
-  },
-  pro: {
-    stt_transcribe: { limit: -1, period: 'daily' },
-    llm_haiku: { limit: 1500, period: 'daily' },
-    llm_sonnet: { limit: 300, period: 'daily' },
-    llm_opus: { limit: 50, period: 'daily' },
-    // 세션 수 기준 (~$0.016/분 mini — 세션당 평균 수 분 가정)
-    realtime_session: { limit: 30, period: 'daily' },
-  },
-  pro_plus: {
-    stt_transcribe: { limit: -1, period: 'daily' },
-    llm_haiku: { limit: -1, period: 'daily' },    // 무제한
-    llm_sonnet: { limit: 1500, period: 'daily' },
-    llm_opus: { limit: 300, period: 'daily' },
-    realtime_session: { limit: 120, period: 'daily' },
-  },
-  team: {
-    stt_transcribe: { limit: -1, period: 'daily' },
-    llm_haiku: { limit: -1, period: 'daily' },    // 무제한
-    llm_sonnet: { limit: 3000, period: 'daily' },
-    llm_opus: { limit: 600, period: 'daily' },
-    realtime_session: { limit: 300, period: 'daily' },
-  },
-  enterprise: {
-    stt_transcribe: { limit: -1, period: 'daily' },
-    llm_haiku: { limit: -1, period: 'daily' },    // 무제한
-    llm_sonnet: { limit: -1, period: 'daily' },   // 무제한
-    llm_opus: { limit: -1, period: 'daily' },     // 무제한
-    realtime_session: { limit: -1, period: 'daily' }, // 무제한
-  },
-}
+/** 모델별 쿼터 정책. 정본은 packages/core/src/plan-catalog.ts `PLAN_QUOTA` (생성 사본 경유). */
+const MODEL_QUOTA: Readonly<Record<Tier, Readonly<Record<QuotaFeature, ModelQuota>>>> = PLAN_QUOTA
 
 /** Anthropic 모델명 → 쿼터 키 매핑 */
 export function modelToQuotaKey(model: string): QuotaFeature {