refactor(wholesale): split monolithic wholesale.ts into focused modules

The wholesale action set was a single 887-line file mixing 8 distinct
concerns: shared types, brand-scoping helpers, order CRUD, customer
CRUD, product CRUD, settings, deposits, notifications, and webhooks.
Split into a wholesale/ directory with one file per concern plus a
barrel re-export for backwards compatibility.

New structure:
- wholesale/types.ts         — type definitions (no "use server")
- wholesale/scope.ts         — resolveBrandId, enforceBrandScope helpers
- wholesale/orders.ts        — order CRUD + dashboard stats (127 lines)
- wholesale/customers.ts     — customer CRUD (94)
- wholesale/products.ts      — product CRUD (100)
- wholesale/settings.ts      — wholesale_settings + public read (86)
- wholesale/deposits.ts      — deposits + bulk actions (84)
- wholesale/notifications.ts — email/SMS notification queue (88)
- wholesale/webhooks.ts      — outbound webhook settings + dispatch (90)
- wholesale/index.ts         — barrel re-export (77 lines)

Each module is now under 155 lines and topically cohesive. Existing
imports of `@/actions/wholesale` keep working unchanged because of the
barrel. New code can import directly from the focused module to keep
its dep graph smaller.

Notable small cleanups inside the split:
- Removed two private helpers that enqueued webhooks by calling the
  RPC directly; consolidated on the public enqueueWholesaleWebhook
  export from webhooks.ts so orders.ts and deposits.ts no longer need
  fire-and-forget duplication.
- recordWholesaleDeposit now correctly accepts the brandId parameter
  (the original signature lacked it despite the docstring implying it).

Verified: tsc clean, 175/175 tests pass, dev server still compiles
all routes. /wholesale/portal returns 500 due to a pre-existing
brand-scope.ts "server-only" issue in the Pages Router chain — not
introduced by this commit.

src/actions/wholesale/index.ts

@@ -0,0 +1,78 @@
+/**
+ * Barrel re-export for the wholesale action set.
+ *
+ * Source modules live next to this file:
+ *   - orders.ts        — order CRUD + dashboard stats
+ *   - customers.ts     — wholesale customer CRUD
+ *   - products.ts      — wholesale product CRUD
+ *   - settings.ts      — wholesale_settings + public read
+ *   - deposits.ts      — deposit recording + bulk actions
+ *   - notifications.ts — email/SMS notification queue
+ *   - webhooks.ts      — outbound webhook settings + dispatch
+ *   - scope.ts         — brand-scoping helpers (resolveBrandId, enforceBrandScope)
+ *   - types.ts         — shared type definitions
+ *
+ * Existing imports of `@/actions/wholesale` keep working. New code should
+ * import directly from the focused modules to keep the dependency graph
+ * tight.
+ */
+
+export type {
+  WholesaleOrder,
+  WholesaleCustomer,
+  WholesaleProduct,
+  NotificationRecipient,
+  WholesaleSettings,
+  WholesaleDashboardStats,
+  WholesaleNotification,
+  WebhookSettings,
+} from "./types";
+
+export { resolveBrandId, enforceBrandScope } from "./scope";
+
+export {
+  getWholesaleOrders,
+  getWholesalePickupOrders,
+  getWholesaleDashboardStats,
+  markWholesaleOrderFulfilled,
+  updateWholesaleOrderStatus,
+  deleteWholesaleOrder,
+} from "./orders";
+
+export {
+  getWholesaleCustomers,
+  saveWholesaleCustomer,
+  deleteWholesaleCustomer,
+} from "./customers";
+
+export {
+  getWholesaleProducts,
+  saveWholesaleProduct,
+  deleteWholesaleProduct,
+} from "./products";
+
+export {
+  getWholesaleSettings,
+  getWholesaleSettingsPublic,
+  saveWholesaleSettings,
+} from "./settings";
+
+export {
+  recordWholesaleDeposit,
+  bulkFulfillWholesaleOrders,
+  bulkRecordWholesaleDeposit,
+} from "./deposits";
+
+export {
+  getWholesaleNotificationStats,
+  getWholesalePendingNotifications,
+  markWholesaleNotificationSent,
+  enqueueWholesaleNotification,
+} from "./notifications";
+
+export {
+  getWebhookSettings,
+  saveWebhookSettings,
+  enqueueWholesaleWebhook,
+  getRecentWebhookActivity,
+} from "./webhooks";