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

src/lib/api-client.ts

@@ -0,0 +1,140 @@
+/** Base path or absolute URL for Odoo JSON API (dev: `/api` + Vite proxy). */
+export const API_BASE_URL = (import.meta.env.VITE_API_BASE_URL?.trim() || "/api").replace(/\/$/, "");
+const BASE_URL = API_BASE_URL;
+
+export function extractApiErrorMessage(data: unknown, status: number, statusText: string): string {
+  if (data && typeof data === "object" && data !== null && "error" in data) {
+    const msg = (data as { error: unknown }).error;
+    if (msg != null && String(msg).trim()) return String(msg);
+  }
+  return `${status} ${statusText}`;
+}
+
+export class ApiError extends Error {
+  constructor(
+    public status: number,
+    public statusText: string,
+    public data: unknown,
+  ) {
+    super(extractApiErrorMessage(data, status, statusText));
+    this.name = "ApiError";
+  }
+}
+
+function getToken(): string | null {
+  return localStorage.getItem("encoach_token");
+}
+
+export function setToken(token: string): void {
+  localStorage.setItem("encoach_token", token);
+}
+
+export function clearToken(): void {
+  localStorage.removeItem("encoach_token");
+}
+
+async function handleResponse<T>(response: Response): Promise<T> {
+  const data = await response.json().catch(() => null);
+
+  if (response.status === 401) {
+    const hadToken = !!getToken();
+    clearToken();
+    // Login failure is also 401 — do not hard-redirect when no session existed.
+    if (hadToken) {
+      window.location.href = "/login";
+    }
+    throw new ApiError(401, response.statusText, data);
+  }
+
+  if (!response.ok) {
+    throw new ApiError(response.status, response.statusText, data);
+  }
+
+  return data as T;
+}
+
+function buildHeaders(extra?: Record<string, string>): Record<string, string> {
+  const headers: Record<string, string> = {
+    "Content-Type": "application/json",
+    ...extra,
+  };
+
+  const token = getToken();
+  if (token) {
+    headers["Authorization"] = `Bearer ${token}`;
+  }
+
+  return headers;
+}
+
+function buildUrl(path: string, params?: Record<string, string | number | boolean | undefined>): string {
+  const url = new URL(`${BASE_URL}${path}`, window.location.origin);
+  if (params) {
+    Object.entries(params).forEach(([key, value]) => {
+      if (value !== undefined) {
+        url.searchParams.set(key, String(value));
+      }
+    });
+  }
+  return url.toString();
+}
+
+export const api = {
+  async get<T>(path: string, params?: Record<string, string | number | boolean | undefined>): Promise<T> {
+    const res = await fetch(buildUrl(path, params), {
+      method: "GET",
+      headers: buildHeaders(),
+    });
+    return handleResponse<T>(res);
+  },
+
+  async post<T>(path: string, body?: unknown): Promise<T> {
+    const res = await fetch(buildUrl(path), {
+      method: "POST",
+      headers: buildHeaders(),
+      body: body ? JSON.stringify(body) : undefined,
+    });
+    return handleResponse<T>(res);
+  },
+
+  async patch<T>(path: string, body?: unknown): Promise<T> {
+    const res = await fetch(buildUrl(path), {
+      method: "PATCH",
+      headers: buildHeaders(),
+      body: body ? JSON.stringify(body) : undefined,
+    });
+    return handleResponse<T>(res);
+  },
+
+  async put<T>(path: string, body?: unknown): Promise<T> {
+    const res = await fetch(buildUrl(path), {
+      method: "PUT",
+      headers: buildHeaders(),
+      body: body ? JSON.stringify(body) : undefined,
+    });
+    return handleResponse<T>(res);
+  },
+
+  async delete<T>(path: string): Promise<T> {
+    const res = await fetch(buildUrl(path), {
+      method: "DELETE",
+      headers: buildHeaders(),
+    });
+    return handleResponse<T>(res);
+  },
+
+  async upload<T>(path: string, formData: FormData): Promise<T> {
+    const token = getToken();
+    const headers: Record<string, string> = {};
+    if (token) {
+      headers["Authorization"] = `Bearer ${token}`;
+    }
+
+    const res = await fetch(buildUrl(path), {
+      method: "POST",
+      headers,
+      body: formData,
+    });
+    return handleResponse<T>(res);
+  },
+};