feat(account): self-service deletion with a 7-day cooling-off period

Request signs out everywhere and freezes paid routes (423 + DB triggers);
signing in within 7 days shows the pending gate with 撤销注销. A periodic
idempotent worker purges personal content afterwards and keeps finance
rows against a tombstoned identity. Read-only admin list.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4f2nya58RoRu4yEmJgRGE

frontend/src/lib/admin/providers.ts

@@ -187,6 +187,7 @@ const resourcePermissions: Record<string, { read: string; write?: string }> = {
   },
   roles: { read: "admin.users.read" },
   customers: { read: "admin.customers.read" },
+  "account-deletions": { read: "admin.customers.read" },
   codes: { read: "admin.access", write: "admin.access" },
   "credit-transactions": { read: "billing.orders.read" },
   consultations: { read: "billing.orders.read" },