feat: trash (soft delete) with admin tool management

- tools: add deletedAt/deletedBy, soft delete via DELETE /tools/:id when
  actor has trash entitlement, else immediate hard delete
- trash endpoints: GET /tools/trash, POST /tools/trash (admin bulk),
  POST /tools/trash/restore, DELETE /tools/trash, POST /tools/trash/empty
- trash feature for premium/enterprise; exclude trashed from all public
  surfaces (browse, categories, features, tags, similar, ratings, costs,
  analytics, redundancy)
- TRASH_RETENTION_DAYS env (0 = keep forever) with hourly purge job
- frontend: /trash page (premium+, restore for all, permanent delete +
  empty for admin), admin Tools tab with multi-select bulk trash,
  sidebar Trash link, tool-detail delete hint

artifacts/api-server/src/middleware/feature.ts

@@ -2,8 +2,8 @@ import { type Request, type Response, type NextFunction } from "express";
 
 const TIER_FEATURES: Record<string, string[]> = {
   free: ["browse", "rate", "search"],
-  premium: ["browse", "rate", "search", "similar-tools", "costs", "redundancy", "analytics-advanced"],
-  enterprise: ["browse", "rate", "search", "similar-tools", "costs", "redundancy", "analytics-advanced", "sso", "audit-export", "api-access"],
+  premium: ["browse", "rate", "search", "similar-tools", "costs", "redundancy", "analytics-advanced", "trash"],
+  enterprise: ["browse", "rate", "search", "similar-tools", "costs", "redundancy", "analytics-advanced", "trash", "sso", "audit-export", "api-access"],
 };
 
 export function getEntitlements(tier: string | undefined, role: string | undefined): string[] {