feat(v3): restructure project + add complete frontend

- Restructure: move backend from new_project/ to backend/
- Add full React/TypeScript frontend (37 pages, 17 services, 16 type defs, 11 query hooks)
- Add docs/ with SRS specs, user stories, and workflow documentation
- Update .gitignore for new directory layout

Workflows implemented:
  WF1 User Signup, WF2 Placement Test, WF3 Exam Configuration,
  WF4 General English Exam, WF5 Course Generation,
  WF6 Entity Student Onboarding, AI Course Generation,
  Adaptive Learning Engine UI, White-Label Branding, Score Release

Made-with: Cursor

frontend/src/services/subscriptions.service.ts

@@ -0,0 +1,36 @@
+import { api } from "@/lib/api-client";
+import type { Package, Payment, Discount, PaginatedResponse, PaginationParams, ApiSuccessResponse } from "@/types";
+
+export const subscriptionsService = {
+  async listPackages(): Promise<Package[]> {
+    return api.get<Package[]>("/packages");
+  },
+
+  async listPayments(params?: PaginationParams): Promise<PaginatedResponse<Payment>> {
+    return api.get<PaginatedResponse<Payment>>("/payments", params as Record<string, string | number | boolean | undefined>);
+  },
+
+  async createStripeCheckout(data: { package_id: number; discount_code?: string }): Promise<{ checkout_url: string }> {
+    return api.post("/stripe/checkout", data);
+  },
+
+  async createPaypalCheckout(data: { package_id: number; discount_code?: string }): Promise<{ approval_url: string }> {
+    return api.post("/paypal/checkout", data);
+  },
+
+  async createPaymobCheckout(data: { package_id: number; discount_code?: string }): Promise<{ payment_url: string }> {
+    return api.post("/paymob/checkout", data);
+  },
+
+  async listDiscounts(params?: PaginationParams): Promise<PaginatedResponse<Discount>> {
+    return api.get<PaginatedResponse<Discount>>("/discounts", params as Record<string, string | number | boolean | undefined>);
+  },
+
+  async createDiscount(data: Partial<Discount>): Promise<Discount> {
+    return api.post<Discount>("/discounts", data);
+  },
+
+  async deleteDiscount(id: number): Promise<ApiSuccessResponse> {
+    return api.delete<ApiSuccessResponse>(`/discounts/${id}`);
+  },
+};