feat(driver-pwa): auth store + ky client + typed driver API (zod)

Co-Authored-By: claude-flow <ruv@ruv.net>

driver-pwa/frontend/src/store/auth.ts

@@ -0,0 +1,21 @@
+import { create } from "zustand";
+import { persist } from "zustand/middleware";
+
+interface AuthState {
+  token: string | null;
+  driverId: number | null;
+  setSession: (token: string, driverId: number) => void;
+  clear: () => void;
+}
+
+export const useAuth = create<AuthState>()(
+  persist(
+    (set) => ({
+      token: null,
+      driverId: null,
+      setSession: (token, driverId) => set({ token, driverId }),
+      clear: () => set({ token: null, driverId: null }),
+    }),
+    { name: "pp-driver-auth" }
+  )
+);