Add NOK pricing catalog, credit ledger, success-based charging, and tier-gated model routing

- PricingCatalog.php: single source of truth for plans (free/plus/pro), top-ups,
  Stripe price env keys, tool costs (0–6 credits), STT variable billing, feature limits
- FreeTier.php: monthly-first credit deduction, ledger (user_tool_credit_ledger),
  STT reservation/settle/release, monthly reset, trial logic
- StripeClient.php: canonical SKUs (plus/pro/topup_100/300/1000), legacy aliases kept
- stripe-checkout.php: subscription vs payment mode, trial gating, catalog metadata
- stripe-webhook.php: idempotent via stripe_events, handles subscription lifecycle +
  invoice.paid renewal + one-time topup credit grants
- All API tools: success-based credit deduction (check before, charge after)
- transcribe.php: file-size heuristic reservation, settle from actual provider duration
- ask.php + LegalTools.php: ToolModels engine resolution — Pro gets gpt-4o
- KorrespondAgent.php + korrespond.php: tier-gated draft deployment —
  Free/Plus gets gpt-4o-mini, Pro gets gpt-4o
- pricing.php: NOK-only, plan cards, top-up packs, Organisation contact card,
  tool cost table, separate monthly/prepaid balance display
- 003_pricing_credit_catalog.sql: ledger and STT reservation tables

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

account.php

@@ -3,6 +3,7 @@ declare(strict_types=1);
 
 require_once __DIR__ . '/includes/bootstrap.php';
 require_once __DIR__ . '/includes/FreeTier.php';
+require_once __DIR__ . '/includes/PricingCatalog.php';
 
 if (!dbnToolsIsAuthenticated()) {
     header('Location: /?return=' . urlencode($_SERVER['REQUEST_URI'] ?? '/account.php'));
@@ -20,11 +21,12 @@ $role  = (string)($authUser['role']  ?? '');
 $detail  = $isSso ? FreeTier::balanceDetail((int)$_SESSION['dbn_tools_sso_uid']) : null;
 $tier    = $detail ? (string)$detail['tier'] : ($isSso ? 'free' : 'caveau');
 
+$catalogPlans = PricingCatalog::plans();
 $tierLabels = [
-    'free'   => ['Free',       '#f3f4f6', '#374151'],
-    'plus'   => ['Plus',       '#ddd6fe', '#5b21b6'],
-    'pro'    => ['Pro',        '#bfdbfe', '#1e40af'],
-    'caveau' => ['CaveauAI',   '#d1fae5', '#065f46'],
+    'free'   => [$catalogPlans['free']['name'], '#f3f4f6', '#374151'],
+    'plus'   => [$catalogPlans['plus']['name'], '#ddd6fe', '#5b21b6'],
+    'pro'    => [$catalogPlans['pro']['name'], '#bfdbfe', '#1e40af'],
+    'caveau' => ['CaveauAI', '#d1fae5', '#065f46'],
 ];
 $tierLabel = $tierLabels[$tier] ?? $tierLabels['free'];
 
@@ -106,7 +108,7 @@ window.DBN_TOOLS_LANG = <?= json_encode($uiLang, JSON_UNESCAPED_UNICODE) ?>;
         </p>
         <p class="account-credits-sub">
             <?= (int)$detail['balance'] ?> <?= htmlspecialchars(dbnToolsT('credits_monthly', $uiLang)) ?>
-            · <?= (int)$detail['bonus_balance'] ?> <?= htmlspecialchars(dbnToolsT('credits_bonus', $uiLang)) ?>
+            · <?= (int)$detail['bonus_balance'] ?> <?= $uiLang === 'no' ? 'forhåndsbetalte' : 'prepaid' ?>
         </p>
 
         <?php if ($renewalLabel): ?>