feat: wave 2 migration (P3, P5, P7 openspec changes)

Implements, verifies, and archives the three remaining Wave 2 changes from
openspec/MIGRATION-PLAN.md.

- add-wallet-settlement (P3): demo recharge, guarded withdrawal freeze and
  one-time admin review, paginated own fund entries, idempotent per-shop
  weekly/monthly settlement statements with commission rate and one-time
  payout confirmation.
- add-merchant-onboarding (P5): personal/enterprise applications with one live
  application per user, guarded review with mandatory rejection reason, and
  transactional shop + owner provisioning returning one-time credentials;
  mall onboarding/status pages and an admin review console.
- add-membership-messaging (P7): platform member levels, append-only growth
  accrual on order completion with guarded one-way leveling, order/shipment/
  refund system messages with unread/read state and soft deletion, plus the
  mall header unread badge.

Backend: migrations 0019-0023, new wallet, settlement, merchant_onboarding,
membership and messaging modules, event hooks in order/fulfillment/aftersale,
and integration suites for each. Shared contract extended and all three
frontends updated; code indexes, domain docs, backend guidelines and the
migration tracker synced.

Verification: cargo test -p vmall-api green twice consecutively; mall, admin
and shop-admin builds pass; browser smoke on every new surface; openspec
validate --all --strict green (33 passed).

The three changes share the @vmall/shared contract, the mall mock adapter and
per-app locale/nav files, so they are committed together to keep every commit
buildable.

openspec/changes/archive/2026-09-24-add-merchant-onboarding/specs/frontend-admin/spec.md

@@ -0,0 +1,20 @@
+## ADDED Requirements
+
+### Requirement: Merchant application review console
+Platform admins SHALL review merchant onboarding applications in a dedicated console entry beside existing platform operations: a status-filtered paginated list and a detail view showing entity kind, entity information, operating categories, contact details, and qualification URL fields. Approving SHALL provision the shop and `shop_owner` account and display the one-time initial credentials exactly once, with copy stating the password cannot be retrieved again. Rejecting SHALL require a reason. Reviewed applications SHALL leave the pending queue immediately.
+
+#### Scenario: review an enterprise application
+- **WHEN** a platform admin opens a pending enterprise application
+- **THEN** the company entity data, operating categories, contact details, and qualification URLs are visible for review
+
+#### Scenario: approve shows one-time credentials
+- **WHEN** a platform admin approves an application
+- **THEN** the created shop owner's initial credentials are shown once and the application moves to the approved list
+
+#### Scenario: reject requires a reason
+- **WHEN** a platform admin attempts to reject without entering a reason
+- **THEN** the action is blocked until a non-empty reason is provided
+
+#### Scenario: entry beside platform operations
+- **WHEN** an authenticated platform admin opens the admin console
+- **THEN** merchant application review is reachable from the console navigation