feat(ml): upload images to ML hosting + show earnings estimate on validate

- Add upload_image() to MeliService using ML /pictures endpoint
- Add get_listing_price() to fetch exact ML fees
- Auto-upload inventory images to ML before validate/publish
- Show fee breakdown and net earnings in validate modal
- Fallback to approximate fees (13-18%) if ML API fails

pos/services/marketplace_external_service.py

@@ -229,6 +229,68 @@ def build_item_payload(
     return payload
 
 
+def _upload_images_to_meli(svc: MeliService, image_urls: list[str]) -> list[str]:
+    """Upload images to MercadoLibre and return their secure URLs.
+
+    If an image is already a ML URL, it's passed through unchanged.
+    """
+    results = []
+    for url in image_urls:
+        if not url:
+            continue
+        # Already a ML hosted image?
+        if "mercadolibre" in url or "mercadoli.com" in url:
+            results.append(url)
+            continue
+        try:
+            pic = svc.upload_image(url)
+            secure_url = pic.get("secure_url") or pic.get("url") or url
+            results.append(secure_url)
+        except Exception as e:
+            logger.warning("Failed to upload image %s to ML: %s", url, e)
+            # Fallback: try using the original URL anyway
+            results.append(url)
+    return results
+
+
+def _calculate_meli_net_price(svc: MeliService, site_id: str, price: float, listing_type_id: str, category_id: str) -> dict:
+    """Calculate net amount after ML commissions.
+
+    Returns dict with fee_amount, net_amount, fee_pct.
+    Falls back to approximate percentages if the API call fails.
+    """
+    try:
+        fee_info = svc.get_listing_price(site_id, price, listing_type_id, category_id)
+        # Response structure varies; try common keys
+        sale_fee = fee_info.get("sale_fee_amount") or fee_info.get("fee_amount") or 0
+        net_amount = fee_info.get("net_amount") or fee_info.get("net_receive_amount")
+        if net_amount is None:
+            net_amount = price - sale_fee
+        return {
+            "fee_amount": float(sale_fee),
+            "net_amount": float(net_amount),
+            "fee_pct": round((sale_fee / price) * 100, 2) if price > 0 else 0,
+            "source": "ml_api",
+        }
+    except Exception as e:
+        logger.warning("Failed to fetch ML listing price for fee calc: %s", e)
+        # Fallback approximations for MLM
+        approx_fees = {
+            "gold_special": 0.13,
+            "gold_pro": 0.16,
+            "gold_premium": 0.18,
+            "free": 0.0,
+        }
+        fee_rate = approx_fees.get(listing_type_id, 0.13)
+        fee_amount = round(price * fee_rate, 2)
+        return {
+            "fee_amount": fee_amount,
+            "net_amount": round(price - fee_amount, 2),
+            "fee_pct": round(fee_rate * 100, 2),
+            "source": "approximation",
+        }
+
+
 def check_meli_shipping_config(svc: MeliService, cfg: dict) -> dict:
     """Check if the user's ML account has the required shipping modes configured.
 
@@ -394,6 +456,17 @@ def validate_items(
             results["invalid"].append({"inventory_id": inv_id, "error": "El producto no tiene imagen"})
             continue
 
+        # Upload images to ML hosting so they are publicly accessible
+        try:
+            ml_images = _upload_images_to_meli(svc, images)
+        except Exception as e:
+            results["invalid"].append({"inventory_id": inv_id, "error": f"Error subiendo imagen a ML: {e}"})
+            continue
+
+        if not ml_images:
+            results["invalid"].append({"inventory_id": inv_id, "error": "No se pudo subir la imagen a MercadoLibre"})
+            continue
+
         title = (custom_data.get("titles") or {}).get(str(inv_id))
         extra_attrs = (custom_data.get("attributes") or {}).get(str(inv_id))
         price = (custom_data.get("prices") or {}).get(str(inv_id), inv["price_1"])
@@ -401,7 +474,7 @@ def validate_items(
         shipping_cost = custom_data.get("shipping_cost")
 
         payload = build_item_payload(
-            inv, images, meli_category_id, price, item_stock,
+            inv, ml_images, meli_category_id, price, item_stock,
             shipping_mode=shipping_mode, listing_type_id=listing_type_id,
             custom_title=title, extra_attributes=extra_attrs,
             shipping_cost=shipping_cost,
@@ -411,7 +484,18 @@ def validate_items(
         try:
             validation = svc.validate_item(payload)
             if validation.get("status") == "valid":
-                results["valid"].append({"inventory_id": inv_id, "validation": validation})
+                # Calculate estimated net earnings after ML fees
+                site_id = cfg.get("meli_site_id", "MLM")
+                fee_calc = _calculate_meli_net_price(svc, site_id, float(price), listing_type_id, meli_category_id)
+                results["valid"].append({
+                    "inventory_id": inv_id,
+                    "validation": validation,
+                    "price": float(price),
+                    "fee_amount": fee_calc["fee_amount"],
+                    "net_amount": fee_calc["net_amount"],
+                    "fee_pct": fee_calc["fee_pct"],
+                    "fee_source": fee_calc["source"],
+                })
             else:
                 errors = validation.get("validation_errors", [])
                 error_msgs = [f"{e.get('field', '')}: {e.get('message', '')}" for e in errors]
@@ -504,6 +588,17 @@ def publish_items(
             results["failed"].append({"inventory_id": inv_id, "error": "El producto no tiene imagen. ML requiere imagen para publicar."})
             continue
 
+        # Upload images to ML hosting so they are publicly accessible
+        try:
+            ml_images = _upload_images_to_meli(svc, images)
+        except Exception as e:
+            results["failed"].append({"inventory_id": inv_id, "error": f"Error subiendo imagen a ML: {e}"})
+            continue
+
+        if not ml_images:
+            results["failed"].append({"inventory_id": inv_id, "error": "No se pudo subir la imagen a MercadoLibre"})
+            continue
+
         title = (custom_data.get("titles") or {}).get(str(inv_id))
         extra_attrs = (custom_data.get("attributes") or {}).get(str(inv_id))
         price = (custom_data.get("prices") or {}).get(str(inv_id), inv["price_1"])
@@ -511,7 +606,7 @@ def publish_items(
         shipping_cost = custom_data.get("shipping_cost")
 
         payload = build_item_payload(
-            inv, images, meli_category_id, price, item_stock,
+            inv, ml_images, meli_category_id, price, item_stock,
             shipping_mode=shipping_mode, listing_type_id=listing_type_id,
             custom_title=title, extra_attributes=extra_attrs,
             shipping_cost=shipping_cost,