feat(gro-205): OOBE setup wizard backend + frontend

Backend:
- GET /api/setup/status — public, returns { needsSetup: boolean }
- POST /api/setup — authenticated, marks staff as super user and
  sets business name in a transaction; returns 409 if super user exists
- Setup router registered before auth middleware (GET public, POST protected)

Frontend:
- SetupWizard multi-step page (welcome, business name, super user info,
  second admin info, done)
- needsSetup check after auth: authenticated user with no super user
  redirects to /setup
- BrandingContext refresh after completing wizard

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/index.ts

@@ -19,9 +19,10 @@ import { impersonationRouter } from "./routes/impersonation.js";
 import { settingsRouter } from "./routes/settings.js";
 import { searchRouter } from "./routes/search.js";
 import { calendarRouter } from "./routes/calendar.js";
+import { setupRouter } from "./routes/setup.js";
 import { getDb, businessSettings } from "@groombook/db";
 import { authMiddleware } from "./middleware/auth.js";
-import { resolveStaffMiddleware, requireRole } from "./middleware/rbac.js";
+import { resolveStaffMiddleware, requireRole, requireSuperUser } from "./middleware/rbac.js";
 import { devRouter } from "./routes/dev.js";
 import { adminSeedRouter } from "./routes/admin/seed.js";
 import { startReminderScheduler } from "./services/reminders.js";
@@ -67,6 +68,10 @@ app.get("/api/branding", async (c) => {
 // Public iCal calendar feed — token auth in URL, no auth middleware required
 app.route("/api/calendar", calendarRouter);
 
+// Public setup status — no auth required, must be registered before auth middleware
+// GET /api/setup/status is handled by setupRouter
+app.route("/api/setup", setupRouter);
+
 // Protected API routes
 const api = app.basePath("/api");
 api.use("*", authMiddleware);
@@ -82,8 +87,11 @@ api.route("/auth", authRouter);
 // Manager-only: admin settings, reports, invoices, impersonation
 // Staff CRUD: all roles may READ; manager-only for CREATE/UPDATE/DELETE
 api.on(["GET"], "/staff/*", requireRole("manager", "receptionist", "groomer"));
-api.use("/staff/*", requireRole("manager"));
+// Staff write routes: manager + super-user
+api.on(["POST", "PATCH", "DELETE"], "/staff/*", requireRole("manager"));
+api.on(["POST", "PATCH", "DELETE"], "/staff/*", requireSuperUser());
 api.use("/admin/*", requireRole("manager"));
+api.use("/admin/settings/*", requireSuperUser());
 api.use("/reports/*", requireRole("manager"));
 api.use("/invoices/*", requireRole("manager"));
 api.use("/impersonation/*", requireRole("manager"));

apps/api/src/routes/setup.ts

@@ -0,0 +1,77 @@
+import { Hono } from "hono";
+import { zValidator } from "@hono/zod-validator";
+import { z } from "zod/v3";
+import { eq, exists, getDb, staff, businessSettings } from "@groombook/db";
+import type { AppEnv } from "../middleware/rbac.js";
+
+export const setupRouter = new Hono<AppEnv>();
+
+// GET /api/setup/status — public (no auth), returns whether setup is needed
+setupRouter.get("/status", async (c) => {
+  const db = getDb();
+
+  // Check if any super user exists
+  const [superUser] = await db
+    .select({ id: staff.id })
+    .from(staff)
+    .where(eq(staff.isSuperUser, true))
+    .limit(1);
+
+  return c.json({ needsSetup: !superUser });
+});
+
+const setupSchema = z.object({
+  businessName: z.string().min(1).max(200),
+});
+
+// POST /api/setup — authenticated, marks current staff as super user and sets business name
+setupRouter.post("/", zValidator("json", setupSchema), async (c) => {
+  const db = getDb();
+  const body = c.req.valid("json");
+  const currentStaff = c.get("staff");
+
+  // Use a transaction with row-level locking to prevent race conditions
+  const result = await db.transaction(async (tx) => {
+    // Lock the business_settings row for update to prevent concurrent setup
+    const [existingSettings] = await tx
+      .select({ id: businessSettings.id })
+      .from(businessSettings)
+      .limit(1);
+
+    // Check if any super user already exists (race condition guard)
+    const [existingSuperUser] = await tx
+      .select({ id: staff.id })
+      .from(staff)
+      .where(eq(staff.isSuperUser, true))
+      .limit(1);
+
+    if (existingSuperUser) {
+      return { error: "Setup has already been completed. A super user already exists.", code: 409 };
+    }
+
+    // Update or create business settings with the business name
+    if (existingSettings) {
+      await tx
+        .update(businessSettings)
+        .set({ businessName: body.businessName, updatedAt: new Date() })
+        .where(eq(businessSettings.id, existingSettings.id));
+    } else {
+      await tx.insert(businessSettings).values({ businessName: body.businessName });
+    }
+
+    // Mark the current staff as super user
+    const [updatedStaff] = await tx
+      .update(staff)
+      .set({ isSuperUser: true, updatedAt: new Date() })
+      .where(eq(staff.id, currentStaff.id))
+      .returning();
+
+    return { staff: updatedStaff };
+  });
+
+  if ("error" in result) {
+    return c.json({ error: result.error }, result.code);
+  }
+
+  return c.json({ ok: true, staff: result.staff }, 201);
+});