fix(payment): resolve PR audit issues

- Add payment navigation to AppSidebar (user orders + admin payment menu group with collapse)
- Add 5 missing nav i18n keys (myOrders, orderManagement, paymentDashboard, paymentConfig, paymentPlans)
- Renumber payment migrations 090-100 → 092-102 to avoid conflict with upstream 090/091
- Remove non-payment sora_client_enabled change, restore upstream purchase_subscription fields
- Remove extra 'data' from SettingsTab type union

backend/migrations/093_payment_audit_logs.sql

@@ -0,0 +1,9 @@
+CREATE TABLE IF NOT EXISTS payment_audit_logs (
+    id BIGSERIAL PRIMARY KEY,
+    order_id VARCHAR(64) NOT NULL,
+    action VARCHAR(50) NOT NULL,
+    detail TEXT NOT NULL DEFAULT '',
+    operator VARCHAR(100) NOT NULL DEFAULT 'system',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+CREATE INDEX IF NOT EXISTS idx_payment_audit_logs_order_id ON payment_audit_logs(order_id);