Dashboard: Placeholder-Cards durch Header-Buttons ersetzen + UI-Feinschliff

- Placeholder-Cards (Neue Session/Neuer Agent) entfernt
- Stattdessen Buttons in den Section-Headern neben den Titeln
- Section-Header h2 Font-Size angepasst
- Agent-Formular: Ego- und Skills-Labels hinzugefügt, Text-Korrektur
- Form-CSS: Gap und Checkbox-Spacing verfeinert, Selektoren präzisiert

wwwroot/js/pages/dashboard.js

@@ -126,12 +126,8 @@ registerPage('dashboard', {
       }
     }
 
-    // Neue Session Placeholder
-    const newSession = document.createElement('div');
-    newSession.className = 'card placeholder clickable';
-    newSession.innerHTML = '<div class="card-body"><div class="card-title">+ Neue Session</div></div>';
-    newSession.addEventListener('click', () => navigateTo('session'));
-    document.getElementById('newSessionCard').appendChild(newSession);
+    // Neue Session Button
+    document.getElementById('newSessionBtn').addEventListener('click', () => navigateTo('session'));
 
     // Agents
     const agentGrid = document.getElementById('agentCards');
@@ -199,11 +195,8 @@ registerPage('dashboard', {
       agentGrid.appendChild(card);
     }
 
-    const placeholder = document.createElement('div');
-    placeholder.className = 'card placeholder clickable';
-    placeholder.innerHTML = '<div class="card-body"><div class="card-title">+ Neuer Agent</div></div>';
-    placeholder.addEventListener('click', () => navigateTo('agent'));
-    document.getElementById('newAgentCard').appendChild(placeholder);
+    // Neuer Agent Button
+    document.getElementById('newAgentBtn').addEventListener('click', () => navigateTo('agent'));
   },
   destroy() {
     if (this._closeCardMenus) {