feat(server/membership): add ai_points plan policy fields

Introduces ai_points_monthly and ai_point_base_chars on the membership
plan policy, exposes them through TenantPlanAccess and MembershipInfo,
and seeds Pro with a 1500-point monthly allowance across the local,
server, and deploy configs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/tenant/app/auth_service.go

@@ -71,6 +71,8 @@ type MembershipInfo struct {
 	EndAt                  *string `json:"end_at"`
 	ArticleGenerationLimit int     `json:"article_generation_limit"`
 	ArticleQuotaCycle      string  `json:"article_quota_cycle"`
+	AIPointsMonthly        int     `json:"ai_points_monthly"`
+	AIPointBaseChars       int     `json:"ai_point_base_chars"`
 	CompanyLimit           int     `json:"company_limit"`
 	ImageStorageBytes      int64   `json:"image_storage_bytes"`
 	ContactAdminOnExpiry   bool    `json:"contact_admin_on_expiry"`
@@ -271,6 +273,8 @@ func (s *AuthService) loadMembershipInfo(ctx context.Context, tenantID int64) (*
 		EndAt:                  formatTimeValuePtr(access.EndAt),
 		ArticleGenerationLimit: access.ArticleGenerationLimit(),
 		ArticleQuotaCycle:      access.ArticleQuotaCycle(),
+		AIPointsMonthly:        access.AIPointsMonthlyLimit(),
+		AIPointBaseChars:       access.AIPointBaseChars(),
 		CompanyLimit:           access.BrandLimit(),
 		ImageStorageBytes:      access.ImageStorageBytes(),
 		ContactAdminOnExpiry:   access.Policy.ContactAdminOnExpiry,

server/internal/tenant/repository/tenant_plan_repo.go

@@ -98,6 +98,38 @@ func (a *TenantPlanAccess) ArticleQuotaCycle() string {
 	}
 }
 
+func (a *TenantPlanAccess) AIPointsMonthlyLimit() int {
+	if a == nil {
+		return 0
+	}
+	return maxInt(a.Policy.AIPointsMonthly, 0)
+}
+
+func (a *TenantPlanAccess) AIPointBaseChars() int {
+	if a == nil || a.Policy.AIPointBaseChars <= 0 {
+		return 1000
+	}
+	return a.Policy.AIPointBaseChars
+}
+
+func (a *TenantPlanAccess) AIPointsWindow(now time.Time) (time.Time, time.Time, *time.Time) {
+	if a == nil {
+		return time.Time{}, time.Time{}, nil
+	}
+
+	windowStart := a.StartAt.UTC()
+	windowEnd := a.EndAt.UTC()
+	cycleStart, cycleEnd := monthlyCycleBounds(windowStart, now.UTC())
+	if cycleStart.Before(windowStart) {
+		cycleStart = windowStart
+	}
+	if !windowEnd.IsZero() && cycleEnd.After(windowEnd) {
+		cycleEnd = windowEnd
+	}
+	resetAt := cycleEnd
+	return cycleStart, cycleEnd, &resetAt
+}
+
 func (a *TenantPlanAccess) ArticleQuotaWindow(now time.Time) (time.Time, time.Time, *time.Time) {
 	if a == nil {
 		return time.Time{}, time.Time{}, nil