feat: async PDF cache i API media putanje za putne naloge

Uvodi background request tok za generiranje PDF-a s 24h cache-om i cleanup taskom preko Celery beat-a. Dodaje notification metadata download_url za ponovno preuzimanje bez regeneracije, API image endpointe za putne naloge i račune, te frontend integraciju za async download i produkcijski prikaz slika.

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

backend/modules/fleet/migrations/0023_generatedworkorderpdf.py

@@ -0,0 +1,39 @@
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import modules.fleet.models
+import uuid
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fleet', '0022_workorderphoto'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='GeneratedWorkOrderPdf',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, help_text='Unikatni identifikator entiteta (UUID).', primary_key=True, serialize=False)),
+                ('created_at', models.DateTimeField(auto_now_add=True, verbose_name='Vrijeme kreiranja')),
+                ('updated_at', models.DateTimeField(auto_now=True, verbose_name='Vrijeme zadnje izmjene')),
+                ('is_active', models.BooleanField(default=True, verbose_name='Aktivan zapis')),
+                ('pdf_type', models.CharField(choices=[('work_order', 'Putni nalog'), ('service_records', 'Servisni zapisi'), ('invoices', 'Računi')], db_index=True, max_length=32, verbose_name='Tip PDF-a')),
+                ('status', models.CharField(choices=[('pending', 'U obradi'), ('ready', 'Spremno'), ('failed', 'Neuspješno')], db_index=True, default='pending', max_length=16, verbose_name='Status')),
+                ('file', models.FileField(blank=True, null=True, upload_to=modules.fleet.models._generated_work_order_pdf_upload_to, verbose_name='PDF datoteka')),
+                ('filename', models.CharField(blank=True, max_length=255, verbose_name='Naziv datoteke')),
+                ('expires_at', models.DateTimeField(blank=True, db_index=True, null=True, verbose_name='Vrijedi do')),
+                ('error_message', models.TextField(blank=True, verbose_name='Poruka greške')),
+                ('requested_by', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='requested_generated_work_order_pdfs', to=settings.AUTH_USER_MODEL, verbose_name='Zatražio')),
+                ('work_order', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='generated_pdfs', to='fleet.workorder', verbose_name='Putni nalog')),
+            ],
+            options={
+                'verbose_name': 'Generirani PDF putnog naloga',
+                'verbose_name_plural': 'Generirani PDF-ovi putnih naloga',
+                'ordering': ['-created_at'],
+            },
+        ),
+    ]
+

backend/modules/fleet/migrations/0024_alter_workorderphoto_created_at_and_more.py

@@ -0,0 +1,35 @@
+# Generated by Django 5.2.15 on 2026-07-17 14:32
+
+import modules.fleet.models
+import uuid
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fleet', '0023_generatedworkorderpdf'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='workorderphoto',
+            name='created_at',
+            field=models.DateTimeField(auto_now_add=True, verbose_name='Vrijeme kreiranja'),
+        ),
+        migrations.AlterField(
+            model_name='workorderphoto',
+            name='id',
+            field=models.UUIDField(default=uuid.uuid4, editable=False, help_text='Unikatni identifikator entiteta (UUID).', primary_key=True, serialize=False),
+        ),
+        migrations.AlterField(
+            model_name='workorderphoto',
+            name='image',
+            field=models.ImageField(upload_to=modules.fleet.models._work_order_photo_upload_to, verbose_name='Fotografija putnog naloga'),
+        ),
+        migrations.AlterField(
+            model_name='workorderphoto',
+            name='updated_at',
+            field=models.DateTimeField(auto_now=True, verbose_name='Vrijeme zadnje izmjene'),
+        ),
+    ]