fix: zamijeni auth polling health endpointom

Dodaje backend /api/health/ endpoint i prebacuje frontend heartbeat sa /api/token/ OPTIONS na /api/health/ GET kako bi se izbjeglo periodicko gadanje auth rute.

Dodaje TTL cache za clientStore (lastFetchedAt + force opcija) kako bi se smanjili redundantni crm/clients pozivi pri navigaciji.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/core/urls.py

@@ -2,14 +2,19 @@
 from django.conf import settings
 from django.conf.urls.static import static
 from django.contrib import admin
+from django.http import JsonResponse
 from django.urls import path, include
 from rest_framework_simplejwt.views import (
     TokenObtainPairView,
     TokenRefreshView,
 )
 
+def api_health(_request):
+    return JsonResponse({'status': 'ok'})
+
 urlpatterns = [
     path('admin/', admin.site.urls),
+    path('api/health/', api_health, name='api_health'),
     
     # Uključujemo rute iz modula (svaki modul ima svoj urls.py)
     path('api/crm/', include('modules.crm.urls')),

frontend/src/stores/clientStore.js

@@ -8,12 +8,25 @@ export const $clients = atom([]);
 export const $clientsLoading = atom(false);
 export const $clientsError = atom(null);
 
-export async function fetchClients(signal) {
+let _lastClientsFetchAt = 0;
+const CLIENTS_FETCH_TTL_MS = 30_000; // 30 sekundi
+
+export async function fetchClients(arg) {
+    const options = (arg && typeof arg === 'object' && !('aborted' in arg))
+        ? arg
+        : { signal: arg };
+    const { signal, force = false } = options;
+
+    if (!force && $clients.get().length > 0 && Date.now() - _lastClientsFetchAt < CLIENTS_FETCH_TTL_MS) {
+        return;
+    }
+
     $clientsLoading.set(true);
     $clientsError.set(null);
     try {
         const data = await api.get('crm/clients/', { signal });
         $clients.set(Array.isArray(data) ? data : (data.results ?? []));
+        _lastClientsFetchAt = Date.now();
     } catch (err) {
         if (err?.name !== 'AbortError') $clientsError.set(err.message ?? 'Greška');
     } finally {
@@ -24,16 +37,19 @@ export async function fetchClients(signal) {
 export async function createClient(payload) {
     const data = await api.post('crm/clients/', payload);
     $clients.set([...$clients.get(), data]);
+    _lastClientsFetchAt = Date.now();
     return data;
 }
 
 export async function updateClient(id, payload) {
     const data = await api.patch(`crm/clients/${id}/`, payload);
     $clients.set($clients.get().map((c) => (c.id === id ? data : c)));
+    _lastClientsFetchAt = Date.now();
     return data;
 }
 
 export async function deleteClient(id) {
     await api.delete(`crm/clients/${id}/`);
     $clients.set($clients.get().filter((c) => c.id !== id));
+    _lastClientsFetchAt = Date.now();
 }

frontend/src/stores/networkStore.js

@@ -4,14 +4,14 @@ export const $isOffline = atom(false);
 
 const API_BASE = import.meta.env.PUBLIC_API_URL || 'http://localhost:8001/api/';
 
-// Heartbeat endpoint: OPTIONS /api/token/
-// DRF odgovara bez 405 greške i dovoljno je za provjeru dostupnosti backenda.
-const HEARTBEAT_URL = new URL('token/', API_BASE).toString();
+// Heartbeat endpoint: GET /api/health/
+// Time izbjegavamo periodično gađanje auth/token endpointa.
+const HEARTBEAT_URL = new URL('health/', API_BASE).toString();
 
 async function provjeriStvarnuVezu() {
     try {
         const response = await fetch(HEARTBEAT_URL, {
-            method: 'OPTIONS',
+            method: 'GET',
             cache: 'no-store',
         });