feat(sync): add delivery cost, discount tracking and import settings

Parse delivery.total and discounts[] from GoMag JSON into new
delivery_cost/discount_total fields. Add app_settings table for
configuring transport/discount CODMAT codes. When configured,
transport and discount are appended as extra articles in the
Oracle import JSON. Reorder Total column in dashboard/logs tables
and show transport/discount breakdown in order detail modals.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/routers/sync.py

@@ -20,6 +20,12 @@ class ScheduleConfig(BaseModel):
     interval_minutes: int = 5
 
 
+class AppSettingsUpdate(BaseModel):
+    transport_codmat: str = ""
+    transport_vat: str = "21"
+    discount_codmat: str = ""
+
+
 # API endpoints
 @router.post("/api/sync/start")
 async def start_sync(background_tasks: BackgroundTasks):
@@ -429,3 +435,23 @@ async def update_schedule(config: ScheduleConfig):
 async def get_schedule():
     """Get current scheduler status."""
     return scheduler_service.get_scheduler_status()
+
+
+@router.get("/api/settings")
+async def get_app_settings():
+    """Get application settings."""
+    settings = await sqlite_service.get_app_settings()
+    return {
+        "transport_codmat": settings.get("transport_codmat", ""),
+        "transport_vat": settings.get("transport_vat", "21"),
+        "discount_codmat": settings.get("discount_codmat", ""),
+    }
+
+
+@router.put("/api/settings")
+async def update_app_settings(config: AppSettingsUpdate):
+    """Update application settings."""
+    await sqlite_service.set_app_setting("transport_codmat", config.transport_codmat)
+    await sqlite_service.set_app_setting("transport_vat", config.transport_vat)
+    await sqlite_service.set_app_setting("discount_codmat", config.discount_codmat)
+    return {"success": True}