Fix: Add validation for Steam Market History data structure

- Check for both assets and results_html (required by backend)
- Removed obsolete 'events' field check
- Add helpful error message if required fields are missing
- Backend needs results_html to parse prices, dates, and transaction types

Author: rainerstudios

background.js

@@ -1074,15 +1074,47 @@ chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
         }
 
         const marketData = await response.json();
-        console.log('[Background] Steam data:', {
+
+        // Log full response for debugging
+        console.log('[Background] Steam Market History Response:', JSON.stringify(marketData, null, 2));
+
+        console.log('[Background] Steam data summary:', {
+          success: marketData.success,
           total_count: marketData.total_count,
-          events: marketData.events?.length || 0
+          has_assets: !!marketData.assets,
+          has_results_html: !!marketData.results_html,
+          has_purchases: !!marketData.purchases,
+          has_listings: !!marketData.listings,
+          pagesize: marketData.pagesize,
+          keys: Object.keys(marketData)
         });
 
-        if (!marketData.events || marketData.events.length === 0) {
+        // Validate Steam Market History response
+        if (!marketData.success) {
+          sendResponse({
+            success: false,
+            error: 'Steam API returned unsuccessful response. Make sure you\'re logged into Steam.'
+          });
+          return;
+        }
+
+        if (marketData.total_count === 0) {
+          sendResponse({
+            success: false,
+            error: 'No transactions found in your Steam Market history'
+          });
+          return;
+        }
+
+        // Backend requires both assets and results_html for parsing
+        if (!marketData.assets || !marketData.results_html) {
+          console.error('[Background] Missing required fields:', {
+            has_assets: !!marketData.assets,
+            has_results_html: !!marketData.results_html
+          });
           sendResponse({
             success: false,
-            error: 'No transactions found in Steam Market history'
+            error: `Missing required data from Steam API. Try navigating to steamcommunity.com/market/myhistory in your browser first, then try syncing again.`
           });
           return;
         }
@@ -1106,16 +1138,17 @@ chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
         console.log('[Background] Import result:', result);
 
         // Store synced transactions count
+        const transactionCount = marketData.total_count || (marketData.events?.length || 0);
         await chrome.storage.local.set({
           lastTransactionSync: Date.now(),
-          syncedTransactions: marketData.events || []
+          syncedTransactions: Array(transactionCount).fill({ synced: true })
         });
 
         sendResponse({
           success: true,
           added: result.added || 0,
           skipped: result.skipped || 0,
-          total_count: marketData.total_count
+          total_count: transactionCount
         });
 
       } catch (error) {