feat: push product images to cloud for the QR menu

local_backend now uploads each product's image file to cloud_backend
during the existing ~5 min menu sync, so the QR menu can show real
photos without needing a manually-set digital_image_url. Only
re-uploads images whose content hash changed since the last push
(Product.cloud_image_hash), to avoid re-sending unchanged binaries
every cycle.

Also adds a manual "sync now" trigger (POST /api/system/sync-menu) and
a matching button in Settings → Operation, for pushing menu/price/image
changes immediately instead of waiting for the next automatic cycle.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

local_backend/services/cloud_sync.py

@@ -15,6 +15,7 @@ License expiry behaviour:
 import asyncio
 import json
 import logging
+import os
 import socket
 from datetime import datetime, timedelta, timezone
 from pathlib import Path
@@ -176,6 +177,52 @@ async def _sync_once():
         license_state.update(expiry_fields)
 
 
+IMAGE_DIR = Path("/app/data/product_images")
+
+
+async def _push_product_images(db, products):
+    """Upload the local image file for each product whose picture changed since
+    the last successful push (tracked via Product.cloud_image_hash), so the
+    public QR menu can show it without needing a manually-set digital_image_url.
+    Skips products that already have a manual digital_image_url override."""
+    import hashlib
+
+    site_numeric_id = license_state.get("site_numeric_id")
+    if not site_numeric_id:
+        return
+
+    for p in products:
+        if p.digital_image_url or not p.image_url:
+            continue
+
+        filename = os.path.basename(p.image_url)
+        filepath = IMAGE_DIR / filename
+        if not filepath.exists():
+            continue
+
+        try:
+            contents = filepath.read_bytes()
+            image_hash = hashlib.sha256(contents).hexdigest()
+            if image_hash == p.cloud_image_hash:
+                continue
+
+            async with httpx.AsyncClient(timeout=20) as client:
+                resp = await client.post(
+                    f"{settings.CLOUD_URL}/api/menu/sync-image",
+                    headers={"X-Site-ID": settings.SITE_ID, "X-Site-Key": settings.SITE_KEY},
+                    data={"product_id": str(p.id)},
+                    files={"file": (filename, contents)},
+                )
+                resp.raise_for_status()
+
+            p.cloud_image_hash = image_hash
+            db.commit()
+            logger.info("Pushed image for product %d to cloud", p.id)
+
+        except Exception as e:
+            logger.warning("Image push failed for product %d: %s", p.id, e)
+
+
 async def _push_menu_snapshot():
     """Serialize all digital-visible products+categories and POST to cloud."""
     if not settings.SITE_ID or not settings.CLOUD_URL:
@@ -189,6 +236,7 @@ async def _push_menu_snapshot():
         try:
             categories = db.query(Category).filter(Category.parent_id == None).all()
             payload_categories = []
+            all_products = []
             for cat in categories:
                 products = (
                     db.query(Product)
@@ -200,6 +248,7 @@ async def _push_menu_snapshot():
                     .order_by(Product.sort_order)
                     .all()
                 )
+                all_products.extend(products)
                 product_list = []
                 for p in products:
                     product_list.append({
@@ -225,26 +274,28 @@ async def _push_menu_snapshot():
                         "sort_order": cat.sort_order,
                         "products": product_list,
                     })
+
+            snapshot_json = json.dumps({"categories": payload_categories})
+
+            # Resolve numeric site_id from license state (set by heartbeat response)
+            site_numeric_id = license_state.get("site_numeric_id")
+            if not site_numeric_id:
+                logger.debug("Menu push skipped — site_numeric_id not yet known")
+                return
+
+            async with httpx.AsyncClient(timeout=15) as client:
+                resp = await client.post(
+                    f"{settings.CLOUD_URL}/api/menu/sync",
+                    headers={"X-Site-ID": settings.SITE_ID, "X-Site-Key": settings.SITE_KEY},
+                    json={"site_id": site_numeric_id, "snapshot_json": snapshot_json},
+                )
+                resp.raise_for_status()
+            logger.info("Menu snapshot pushed (%d categories)", len(payload_categories))
+
+            await _push_product_images(db, all_products)
         finally:
             db.close()
 
-        snapshot_json = json.dumps({"categories": payload_categories})
-
-        # Resolve numeric site_id from license state (set by heartbeat response)
-        site_numeric_id = license_state.get("site_numeric_id")
-        if not site_numeric_id:
-            logger.debug("Menu push skipped — site_numeric_id not yet known")
-            return
-
-        async with httpx.AsyncClient(timeout=15) as client:
-            resp = await client.post(
-                f"{settings.CLOUD_URL}/api/menu/sync",
-                headers={"X-Site-ID": settings.SITE_ID, "X-Site-Key": settings.SITE_KEY},
-                json={"site_id": site_numeric_id, "snapshot_json": snapshot_json},
-            )
-            resp.raise_for_status()
-        logger.info("Menu snapshot pushed (%d categories)", len(payload_categories))
-
     except Exception as e:
         logger.warning("Menu snapshot push failed: %s", e)