Phase 5.x payment catalog + customer-app splash/register polish

Payment catalog (Phase 5.x — see requirement/phase5-payment-catalog-plan.md):
- New tables payment_method_groups + payment_methods with seed (3 groups,
  10 methods; GoPay seeded inactive pending Xendit channel confirmation).
- payment-catalog.service.js with two-layer cache (60s in-process + 1h
  Valkey) and config:invalidate pub/sub fanout. Mutator API + casing-
  tolerant findActiveMethodByCode for downstream validation.
- App-facing GET /api/client/payment-methods returns pre-grouped JSON,
  active-only, empty groups dropped server-side.
- POST /api/client/payment-requests now validates `method` against the
  catalog (INVALID_PAYMENT_METHOD 422) and stamps
  product_metadata.preferred_payment_code (upper-cased).
- Control-center /internal/payment-{groups,methods}{,/:id,/reorder}
  endpoints (full CRUD + idempotent reorder). New Payment Catalog page
  wired into the CC nav.
- Customer app renders the catalog as collapsible groups (first expanded)
  via paymentCatalogProvider; QRIS-only hardcoded fallback on 5xx so
  checkout never hard-fails. Replaces the hardcoded _PayMethod enum.
- 10 brand SVGs (~63KB) bundled in client_app/assets/payment_icons/ from
  github.com/hafidznoor/idn-finlogos. Xendit's per-channel media-asset
  pages were planned but found decommissioned during implementation —
  switched to idn-finlogos with the standard "channels-we-accept"
  trademark posture. See assets/payment_icons/README.md for the workflow
  to add new methods.
- 16 vitest cases covering the service + cache; full backend suite green
  (162/162).

Customer-app splash + register polish:
- Splash rewritten per figma S1: warm vertical gradient, two ImageFiltered
  radial orbs, 96×96 rounded-square logo tile, "HaloBestie" + "kamu gak
  harus ngerasain ini sendirian." Self-driving navigation via context.go
  after a 2.5s post-frame timer (native Android splash burns ~1-1.5s
  before Flutter paints — 1s timer yielded near-zero visible duration).
  Router early-returns null for isSplash so it never moves us off /splash
  on its own.
- 3-page onboarding carousel removed: user clarified the new splash
  REPLACES that carousel. Dropped /onboarding route, OnboardingScreen,
  onboardingDoneProvider + gating, dead splash_{1,2,3}.png + the
  splash_chat_hebat.png Flutter asset. Phase 4 /onboarding/* subroutes
  untouched; Android-native launch_background drawable left alone.
- Register screen (login-by-phone) polished: circular pink back button +
  72×72 logo badge (same brandLogoBg pink as splash, Transform.scale 1.4
  to fill the tile). Step-dots indicator removed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

client_app/lib/features/payment/widgets/payment_icon.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_svg/flutter_svg.dart';
+
+import '../../../core/theme/halo_tokens.dart';
+
+/// Slugs we ship SVGs for. Keep this in sync with `assets/payment_icons/`.
+/// When a brand mark is added to the bundle (drop the SVG into the asset
+/// dir), add its slug here. Anything not in this set renders the placeholder.
+///
+/// Source: idn-finlogos (github.com/hafidznoor/idn-finlogos) — see
+/// `assets/payment_icons/NOTICE_IDN_FINLOGOS.txt` for licensing terms.
+const Set<String> _kBundledSlugs = {
+  'qris',
+  'ovo',
+  'dana',
+  'shopeepay',
+  'gopay',
+  'bca',
+  'mandiri',
+  'bni',
+  'bri',
+  'permata',
+};
+
+/// Renders a payment-method brand mark by slug (`payment_methods.icon`).
+/// Falls back to a generic credit-card placeholder when the slug isn't
+/// bundled. Slugs are kept lower-case by convention.
+class PaymentIcon extends StatelessWidget {
+  final String? slug;
+  final double size;
+  final Color color;
+
+  const PaymentIcon({
+    super.key,
+    required this.slug,
+    this.size = 24,
+    this.color = HaloTokens.brandDark,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isBundled = slug != null && _kBundledSlugs.contains(slug);
+    final asset = isBundled
+        ? 'assets/payment_icons/$slug.svg'
+        : 'assets/payment_icons/placeholder.svg';
+
+    // Brand SVGs ship with their canonical colors and must NOT be tinted;
+    // the placeholder is mono-color and DOES want the brand-dark tint.
+    return SvgPicture.asset(
+      asset,
+      width: size,
+      height: size,
+      colorFilter: isBundled ? null : ColorFilter.mode(color, BlendMode.srcIn),
+    );
+  }
+}