Add product scanning functionality to eBay extension

- Introduced a new scanProductsForAccount feature in the background script to handle product scanning requests.
- Implemented a timeout mechanism for scan requests to enhance reliability.
- Updated content scripts to parse product lists and extract relevant data from eBay storefronts.
- Enhanced error handling and logging for better debugging and user feedback.
- Added methods to extract items sold and shop names from eBay profiles.

Extension/content-script.js

@@ -3,20 +3,62 @@
 
 const MESSAGE_SOURCE = "eship-webapp";
 
-// Markiere Extension als verfügbar
-// #region agent log
-try {
-  console.log('[ESHIP-CONTENT] Content script loaded');
-  if (typeof window !== 'undefined') {
-    window.__EBAY_EXTENSION__ = true;
-    console.log('[ESHIP-CONTENT] window.__EBAY_EXTENSION__ set to true');
-  } else {
-    console.error('[ESHIP-CONTENT] window is undefined!');
+// Markiere Extension als verfügbar - MEHRFACH versuchen, da Timing variieren kann
+function setExtensionFlag() {
+  try {
+    const hasChrome = typeof chrome !== 'undefined';
+    const hasRuntime = hasChrome && chrome.runtime;
+    const runtimeId = hasRuntime ? chrome.runtime.id : null;
+    if (typeof window !== 'undefined' && hasChrome && hasRuntime && runtimeId) {
+      window.__EBAY_EXTENSION__ = true;
+      window.__EBAY_EXTENSION_ID__ = runtimeId; // Extension-ID für chrome.runtime.sendMessage
+      console.log('[ESHIP-CONTENT] window.__EBAY_EXTENSION__ set to true, ID:', runtimeId);
+      return true;
+    }
+  } catch (e) {
+    console.error('[ESHIP-CONTENT] Error setting flag:', e);
   }
-} catch (e) {
-  console.error('[ESHIP-CONTENT] Error setting flag:', e);
+  return false;
 }
-// #endregion
+
+// Versuche Flag sofort zu setzen
+console.log('[ESHIP-CONTENT] Content script loaded');
+if (!setExtensionFlag()) {
+  // Wenn window nicht verfügbar, warte auf DOMContentLoaded oder document.readyState
+  if (document.readyState === 'loading') {
+    document.addEventListener('DOMContentLoaded', () => {
+      setExtensionFlag();
+    });
+  } else {
+    // DOM ist bereits geladen, versuche nochmal
+    setTimeout(() => {
+      setExtensionFlag();
+    }, 0);
+  }
+}
+
+// Sende Extension-ID an Web-App via postMessage (da Content Script Isolation verhindert, dass window-Properties geteilt werden)
+// Die Web-App kann dann die Extension-ID in ihrem eigenen Context speichern
+function sendExtensionIdToWebApp() {
+  try {
+    const runtimeId = chrome.runtime?.id;
+    if (runtimeId) {
+      // Sende Extension-ID an Web-App
+      window.postMessage({
+        source: "eship-extension",
+        type: "EXTENSION_ID",
+        extensionId: runtimeId
+      }, "*");
+    }
+  } catch (e) {
+    console.error('[ESHIP-CONTENT] Error sending extension ID:', e);
+  }
+}
+
+// Sende Extension-ID beim Laden
+sendExtensionIdToWebApp();
+// Auch nach kurzer Verzögerung nochmal (falls Web-App noch nicht bereit ist)
+setTimeout(sendExtensionIdToWebApp, 500);
 
 window.addEventListener("message", (event) => {
   // Sicherheitscheck: Nur Nachrichten von derselben Origin akzeptieren