feat: integrate Amazon Vendor Stock data across all views and fix local data loading

services/dataProcessor.ts

@@ -1694,6 +1694,68 @@ export const calculateForecastViewData = (
     });
 };
 
+export const processVendorStockExcel = async (fileOrBuffer: File | ArrayBuffer): Promise<Map<string, { eu: number; uk: number }>> => {
+    try {
+        const arrayBuffer = fileOrBuffer instanceof File
+            ? await fileOrBuffer.arrayBuffer()
+            : fileOrBuffer;
+        const workbook = XLSX.read(arrayBuffer, { type: 'array' });
+        const sheetName = workbook.SheetNames[0];
+        const worksheet = workbook.Sheets[sheetName];
+        const jsonData: any[][] = XLSX.utils.sheet_to_json(worksheet, { header: 1 });
+
+        const vendorStockMap = new Map<string, { eu: number; uk: number }>();
+
+        // Find header row (it contains "ASIN")
+        let headerRowIndex = -1;
+        for (let i = 0; i < Math.min(jsonData.length, 20); i++) {
+            if (jsonData[i] && jsonData[i].includes('ASIN')) {
+                headerRowIndex = i;
+                break;
+            }
+        }
+
+        if (headerRowIndex === -1) {
+            console.warn("Could not find header row in Vendor Stock Excel");
+            return vendorStockMap;
+        }
+
+        // Skip headers
+        // A (0): ASIN
+        // D (3): Marketplace (Country)
+        // P (15): Sellable on hands units
+        for (let i = headerRowIndex + 1; i < jsonData.length; i++) {
+            const row = jsonData[i];
+            if (!row || row.length < 16) continue;
+
+            const asin = String(row[0] || '').trim().toUpperCase();
+            const marketplace = String(row[3] || '').trim().toLowerCase();
+            const stockValue = parseUnits(String(row[15] || '0'));
+
+            if (!asin) continue;
+
+            if (!vendorStockMap.has(asin)) {
+                vendorStockMap.set(asin, { eu: 0, uk: 0 });
+            }
+
+            const current = vendorStockMap.get(asin)!;
+
+            // Map to UK or EU
+            if (marketplace.includes('uk') || marketplace.includes('kingdom') || marketplace === 'gb') {
+                current.uk += stockValue;
+            } else {
+                // Assume everything else is Pan-EU for now if it's not UK
+                current.eu += stockValue;
+            }
+        }
+
+        return vendorStockMap;
+    } catch (error) {
+        console.error("Error processing Vendor Stock Excel:", error);
+        throw error;
+    }
+};
+
 export const processStockExcel = async (fileOrBuffer: File | ArrayBuffer): Promise<Map<string, number>> => {
     try {
         const arrayBuffer = fileOrBuffer instanceof File