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

server/test/gemini-helpers.test.js

@@ -4,10 +4,11 @@ import { PRICING, calcCost, buildAnalysisPrompt } from "../gemini-helpers.js";
 
 describe("PRICING table", () => {
   test("includes all current production model slugs", () => {
-    assert.ok(PRICING["gemini-3-flash-preview"]);
-    assert.ok(PRICING["gemini-3-pro-preview"]);
     assert.ok(PRICING["gemini-3.1-pro-preview"]);
+    assert.ok(PRICING["gemini-2.5-pro"]);
+    assert.ok(PRICING["gemini-3-flash-preview"]);
     assert.ok(PRICING["gemini-2.5-flash"]);
+    assert.ok(PRICING["gemini-3.1-flash-lite"]);
   });
 
   test("has a 'default' fallback row", () => {
@@ -66,7 +67,7 @@ describe("calcCost", () => {
   });
 
   test("formats >$0.01 totals as $X.XXXX", () => {
-    const cost = calcCost("gemini-3-pro-preview", {
+    const cost = calcCost("gemini-3.1-pro-preview", {
       promptTokenCount: 1_000_000,
       candidatesTokenCount: 0,
       thoughtsTokenCount: 0,