feat(api): add typed API client, auth context, and integrate registration/login flows; docs: add backend integration guide and .env.example

README.md

@@ -55,3 +55,41 @@ src/
 - `npm run dev` - Runs the app in development mode with Vite
 - `npm run build` - Builds the app for production
 - `npm run preview` - Preview the production build locally
+
+## Backend Integration Guide
+
+Base URL: `https://api.pennyzo.com/api/v1/general` (configurable via `VITE_API_BASE_URL`)
+
+- HTTP client: `src/lib/http.ts` (handles JSON, form, and auth header)
+- Auth state: `src/context/AuthContext.tsx` (stores JWT token, loads `auth/me`)
+- Endpoints: `src/lib/api/*`
+  - `system.ts`: `/system/health`, `/system/`
+  - `auth.ts`: `/auth/*` (verify email/resend/login/me/forgot/reset/change)
+  - `registration.ts`: `/registration/*` (register + rules + health)
+  - `users.ts`: `/users/*` (profile/company/gst/upgrade/stats/membership-info)
+
+### UI flows → endpoints
+
+- Registration modal `WaitlistForm`: `POST /registration/register`
+  - Maps UI fields to API and enforces rules:
+    - GST Registered → send `gst_number`, `cin_number=null`, `pan_number=null`
+    - Non-GST PRIVATE_LIMITED/LLP → send `cin_number`, `pan_number=null`
+    - Non-GST PARTNERSHIP/PROPRIETORSHIP/SOLE_INDIVIDUAL/OTHERS → send `pan_number`, `cin_number=null`
+- Login modal `LoginPage`: `POST /auth/login` as `application/x-www-form-urlencoded` with `username`, `password`; then `GET /auth/me`.
+- Forgot password button calls `POST /auth/forgot-password` with the entered email.
+
+### Types and config
+
+- Types: `src/types/api.ts`
+- Config: set `VITE_API_BASE_URL` in `.env` (see `.env.example`).
+
+### Quick health check
+
+```
+curl -X GET "https://api.pennyzo.com/api/v1/general/system/health"
+```
+
+### Error handling
+
+- Non-2xx responses are surfaced with `error.message` when provided by backend.
+- Invalid token on `auth/me` clears stored token.