feat: unified gravity system - VIP members consume gravity instead of unlimited; add monthly gravity top-up cron

backend/src/modules/member/member.controller.ts

@@ -54,6 +54,12 @@ export class MemberController {
 
     return {
       interview: { dailyFreeLimit: FREE_DAILY_LIMIT, maxRoundsFree: 5, maxRoundsVip: 10 },
+      gravityRates: pricing.gravityRates,
+      products: {
+        interview: { price: pricing.interview.pricePerSession, title: 'AI 模拟面试单次', gravity: pricing.gravityRates.interviewPerUse },
+        optimize: { price: pricing.resumeOptimize.pricePerOptimize, title: '简历优化单次', gravity: pricing.gravityRates.optimizePerUse },
+        download: { price: pricing.resumeDownload.pricePerDownload, title: '简历下载', gravity: pricing.gravityRates.downloadPerUse },
+      },
       plans,
     }
   }
@@ -66,6 +72,7 @@ export class MemberController {
       plan: user.plan,
       planName: user.plan === 'growth' ? '成长版' : user.plan === 'sprint' ? '冲刺版' : '免费版',
       remaining: user.remaining,
+      gravity: user.gravity ?? 0,
       dailyLimit: user.plan !== 'free' ? 999 : FREE_DAILY_LIMIT,
       vipExpireAt: user.vipExpireAt,
       sprintExpireAt: user.sprintExpireAt,
@@ -101,7 +108,7 @@ export class MemberController {
       user.plan = 'growth'
       user.vipExpireAt = expireAt
     }
-    await this.quotaService.setPlanQuota(userId, order.plan, planCfg.credits)
+    await this.quotaService.setPlanQuota(userId, planCfg.gravityPerMonth)
     return { success: true, plan: user.plan, planName: user.plan === 'growth' ? '成长版' : '冲刺版', expireAt }
   }