feat: UX Cleanup & Critical TaskBeat Fix

UX Improvements:
- Tasks page: Remove 'Create new task' form (orchestrator handles all)
- Orchestrator: Simplified to single 'Prompt' section, removed 'Tasks verteilen'
- Orchestrator: Removed 'Klassisch senden' button (live-only responses)
- Orchestrator: Removed 'Aktive Agenten' display (redundant with dashboard)

Critical Fix:
- TaskBeat now reads pending tasks from DATABASE instead of in-memory array
- All status updates (pending→in_progress→completed) now persist to DB
- Fixes issue where tasks created via API/UI were not being processed
- Agent_key updates also synced to DB

This fixes the bug where Task #1 was stuck in pending status.

templates/tasks.html

@@ -8,50 +8,7 @@
 </div>
 
 <div class="row g-4">
-  <div class="col-lg-4">
-    <div class="card mb-3">
-      <div class="card-header bg-success">
-        <h5 class="mb-0">Neuen Task erstellen</h5>
-      </div>
-      <div class="card-body">
-        <form method="POST" action="/tasks">
-          <div class="mb-3">
-            <label for="title" class="form-label">Titel</label>
-            <input type="text" class="form-control" id="title" name="title" placeholder="Task-Titel" required>
-          </div>
-          <div class="mb-3">
-            <label for="description" class="form-label">Beschreibung</label>
-            <textarea class="form-control" id="description" name="description" rows="3"
-              placeholder="Optionale Beschreibung"></textarea>
-          </div>
-          <div class="mb-3">
-            <label for="assigned_agent" class="form-label">Agent (optional)</label>
-            <select class="form-select" id="assigned_agent" name="assigned_agent">
-              <option value="">— Agent wählen —</option>
-              {% for key, agent in agents.items() %}
-              <option value="{{ key }}">{{ agent.name }}</option>
-              {% endfor %}
-            </select>
-          </div>
-          <button type="submit" class="btn btn-success w-100">Task erstellen</button>
-        </form>
-      </div>
-    </div>
-    
-    <div class="card">
-      <div class="card-header bg-info">
-        <h5 class="mb-0">ℹ️ Info</h5>
-      </div>
-      <div class="card-body">
-        <p class="mb-0" style="font-size:0.875rem;color:var(--text-muted);">
-          Tasks werden automatisch alle 10 Sekunden vom TaskBeat verarbeitet.
-          <br>Diese Seite aktualisiert sich automatisch alle 15 Sekunden wenn Tasks aktiv sind.
-        </p>
-      </div>
-    </div>
-  </div>
-
-  <div class="col-lg-8">
+  <div class="col-12">
     <div class="card">
       <div class="card-header bg-primary d-flex justify-content-between align-items-center">
         <h5 class="mb-0">Alle Tasks</h5>