fix(gtm): Fix white screen and implement URL persistence v2.6.1

- Fixed TypeError in SessionBrowser by adding defensive checks for the sessions array.
- Implemented mandatory URL persistence: The research URL is now saved in DB, shown in UI, and included in reports.
- Added 'Start New Analysis' button to the session browser for better UX flow.
- Updated documentation to reflect v2.6.1 changes.

gtm-architect/components/SessionBrowser.tsx

@@ -1,56 +1,79 @@
 import React from 'react';
 import { ProjectHistoryItem } from './types';
 import './SessionBrowser.css';
+import { Plus, FileText } from 'lucide-react';
 
 interface SessionBrowserProps {
   sessions: ProjectHistoryItem[];
   onLoadSession: (projectId: string) => void;
   onDeleteSession: (projectId: string) => void;
+  onStartNew: () => void;
 }
 
-const SessionBrowser: React.FC<SessionBrowserProps> = ({ sessions, onLoadSession, onDeleteSession }) => {
+const SessionBrowser: React.FC<SessionBrowserProps> = ({ sessions, onLoadSession, onDeleteSession, onStartNew }) => {
   
   const getCategoryIcon = (category: string) => {
+    // Return an icon based on the category, default to a generic robot
+    if (!category) return '🤖';
     switch (category.toLowerCase()) {
       case 'reinigungsroboter':
-        return '🧹'; // Sweeping broom emoji
+        return '🧹';
       case 'serviceroboter':
-        return '🛎️'; // Bellhop bell emoji
+        return '🛎️';
       case 'transportroboter':
-        return '📦'; // Package emoji
+        return '📦';
       case 'security roboter':
-        return '🛡️'; // Shield emoji
+        return '🛡️';
       default:
-        return '🤖'; // Default robot emoji
+        return '🤖';
     }
   };
 
   return (
     <div className="session-browser">
-      <h2>Gespeicherte Sitzungen</h2>
-      <div className="session-grid">
-        {sessions.map((session) => (
-          <div key={session.id} className="session-card">
-            <div className="card-header">
-                <span className="category-icon">{getCategoryIcon(session.productCategory)}</span>
-                <h3 title={session.productName}>{session.productName}</h3>
-            </div>
-            {/* Thumbnail placeholder */}
-            <div className="thumbnail-placeholder">
-              <span>🖼️</span>
-              <p>Thumbnail</p>
-            </div>
-            <div className="card-content">
-              <p className="product-description">{session.productDescription}</p>
-              <p className="last-updated">Zuletzt bearbeitet: {new Date(session.updated_at).toLocaleString()}</p>
-            </div>
-            <div className="card-actions">
-              <button onClick={() => onLoadSession(session.id)} className="load-btn">Laden</button>
-              <button onClick={() => onDeleteSession(session.id)} className="delete-btn">Löschen</button>
-            </div>
-          </div>
-        ))}
+      <div className="browser-header">
+        <h2 className="flex items-center gap-2"><FileText size={28}/> Gespeicherte Sitzungen</h2>
+        <button onClick={onStartNew} className="start-new-btn">
+          <Plus size={16}/> Neue Analyse starten
+        </button>
       </div>
+
+      {(!sessions || sessions.length === 0) ? (
+        <div className="empty-state">
+            <p>Keine gespeicherten Sitzungen gefunden.</p>
+            <button onClick={onStartNew} className="start-new-btn-secondary">
+                Jetzt eine neue Analyse starten
+            </button>
+        </div>
+      ) : (
+        <div className="session-grid">
+          {sessions.map((session) => (
+            <div key={session.id} className="session-card">
+              <div className="card-header">
+                  <span className="category-icon">{getCategoryIcon(session.productCategory)}</span>
+                  <h3 title={session.productName}>{session.productName || 'Unbenannt'}</h3>
+              </div>
+              <div className="thumbnail-placeholder">
+                <span>🖼️</span>
+                <p>Thumbnail</p>
+              </div>
+              <div className="card-content">
+                <p className="product-description">{session.productDescription || 'Keine Beschreibung verfügbar.'}</p>
+                <p className="source-url">
+                    <a href={session.sourceUrl} target="_blank" rel="noopener noreferrer">
+                        Quelle anzeigen
+                    </a>
+                </p>
+                <p className="last-updated">Zuletzt bearbeitet: {new Date(session.updated_at).toLocaleString()}</p>
+              </div>
+              <div className="card-actions">
+                <button onClick={() => onLoadSession(session.id)} className="load-btn">Laden</button>
+                <button onClick={() => onDeleteSession(session.id)} className="delete-btn">Löschen</button>
+              </div>
+            </div>
+          ))}
+        </div>
+      )}
     </div>
   );
 };