Add multi-tenant cloud mode: self-serve purchase, credit metering, core-decoupling

Introduces RECAP_MODE=multi alongside single-mode self-host:
- Tenant auth + accounts (magic-link via System SMTP), per-tenant credit pool,
  anonymous trial minting with per-IP/-64 caps
- Self-serve Pro/Max purchase: inline Lightning (BTCPay) + card (Zaprite),
  prepaid 30-day periods, expiry-reminder emails
- Core-decoupling: relay owns cloud tier/expiry keyed by Recaps user-id
- SQLite (better-sqlite3) schema for multi-mode; filesystem unchanged for single
- StartOS actions/versions through 0.2.155

startos/versions/v0.2.82.ts

@@ -0,0 +1,12 @@
+import { VersionInfo } from '@start9labs/start-sdk'
+
+export const v_0_2_82 = VersionInfo.of({
+  version: '0.2.82:0',
+  releaseNotes: {
+    en_US: 'Per-user relay-state cache (Phase 1F): the in-memory snapshot of the relay\'s credits balance is now keyed by per-identity credit-key so an admin and a tenant hitting /api/relay/status in the same process can\'t clobber each other\'s view. Plus account deletion (Phase 1G): tenants get a Danger Zone "Delete account" action in their lite settings (two-step confirm); admins get a per-row Delete button in the Tenants list (refuses to delete other admins or self). Cascades sessions, tenant_credits, library_meta, and removes the per-user /data/history/<id>/ folder. Polished sign-in error page with brand-styled card + "Get a new sign-in link" CTA.',
+  },
+  migrations: {
+    up: async ({ effects }) => {},
+    down: async ({ effects }) => {},
+  },
+})