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/v0.2.94.ts

@@ -0,0 +1,12 @@
+import { VersionInfo } from '@start9labs/start-sdk'
+
+export const v_0_2_94 = VersionInfo.of({
+  version: '0.2.94:0',
+  releaseNotes: {
+    en_US: 'Three Apple-Podcast + anon UX bug fixes. (1) Apple Podcast EPISODE URLs (with ?i=<id>) no longer get mis-flagged as subscribe-able shows — the regex\'s negative lookahead was positioned wrong, matching both show AND episode URLs. Replaced with URL.searchParams parsing on both frontend and server. (2) The Subscribe button for non-Pro users no longer 401s with a raw "auth_required" — the banner now reads "Channel detected — Pro account required" with an upgrade CTA that opens the 3-tier signup modal (anon) or the buy-license modal (free signed-in). (3) "Buy more credits" is now visible to anonymous visitors who see their pre-trial credit allowance. Desktop toolbar gets a new branch in renderToolbarStatus that surfaces "N free credits ready" + the "+ Buy more" button using state.account.available_trial_credits; mobile hamburger menu gets a parallel "Buy more credits" item below the credit count line.',
+  },
+  migrations: {
+    up: async ({ effects }) => {},
+    down: async ({ effects }) => {},
+  },
+})