feat(auth): implement user authentication with JWT and NextAuth

- Added user registration and login functionality with JWT authentication.
- Created auth controller, service, and module in the backend.
- Implemented user model and user products management.
- Integrated NextAuth for session management on the frontend.
- Added middleware for protecting routes and handling public access.
- Updated frontend API routes to include authorization headers.
- Enhanced recipe and user product models to support ownership and visibility.
- Created registration and login pages in the frontend.
- Added necessary types for NextAuth session management.

frontend/app/inventory/actions.ts

@@ -2,14 +2,17 @@
 
 import { revalidatePath } from 'next/cache';
 import { API_BASE } from '../../lib/api';
+import { getAuthHeaders } from '../../lib/auth-headers';
 
 export async function createProduct(formData: FormData) {
   const name = String(formData.get('name') || '').trim();
+  const authHeaders = await getAuthHeaders();
 
   const res = await fetch(`${API_BASE}/api/products`, {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',
+      ...authHeaders,
     },
     body: JSON.stringify({ name }),
     cache: 'no-store',
@@ -51,6 +54,7 @@ export async function createInventoryItem(formData: FormData) {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',
+      ...(await getAuthHeaders()),
     },
     body: JSON.stringify(payload),
     cache: 'no-store',
@@ -91,6 +95,7 @@ export async function updateInventoryItem(formData: FormData) {
     method: 'PATCH',
     headers: {
       'Content-Type': 'application/json',
+      ...(await getAuthHeaders()),
     },
     body: JSON.stringify(payload),
     cache: 'no-store',
@@ -112,6 +117,7 @@ export async function updateCanonicalName(formData: FormData) {
     method: 'PATCH',
     headers: {
       'Content-Type': 'application/json',
+      ...(await getAuthHeaders()),
     },
     body: JSON.stringify({ canonicalName }),
     cache: 'no-store',
@@ -133,6 +139,7 @@ export async function mergeProducts(formData: FormData) {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',
+      ...(await getAuthHeaders()),
     },
     body: JSON.stringify({
       sourceProductId,
@@ -166,6 +173,7 @@ export async function consumeInventoryItem(formData: FormData) {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',
+      ...(await getAuthHeaders()),
     },
     body: JSON.stringify(payload),
     cache: 'no-store',