Add execution cleanup functionality

Changes:
- Added DELETE /api/executions/:id endpoint
- Added "Clear Completed" button to Executions tab
- Deletes all completed and failed executions
- Broadcasts execution_deleted event to update all clients
- Shows count of deleted executions

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

public/index.html

@@ -633,7 +633,8 @@
         <div id="executions" class="tab-content">
             <div class="card">
                 <h3>Execution History</h3>
-                <button onclick="refreshData()">🔄 Refresh</button>
+                <button onclick="refreshData()">[ 🔄 Refresh ]</button>
+                <button onclick="clearCompletedExecutions()" style="margin-left: 10px;">[ 🗑️ Clear Completed ]</button>
                 <div id="executionList"><div class="loading">Loading...</div></div>
             </div>
         </div>
@@ -834,6 +835,32 @@
             }
         }
 
+        async function clearCompletedExecutions() {
+            if (!confirm('Delete all completed and failed executions?')) return;
+
+            try {
+                const response = await fetch('/api/executions');
+                const executions = await response.json();
+
+                const toDelete = executions.filter(e => e.status === 'completed' || e.status === 'failed');
+
+                if (toDelete.length === 0) {
+                    alert('No completed or failed executions to delete');
+                    return;
+                }
+
+                for (const execution of toDelete) {
+                    await fetch(`/api/executions/${execution.id}`, { method: 'DELETE' });
+                }
+
+                alert(`Deleted ${toDelete.length} execution(s)`);
+                refreshData();
+            } catch (error) {
+                console.error('Error clearing executions:', error);
+                alert('Error clearing executions');
+            }
+        }
+
         async function executeWorkflow(workflowId, name) {
             if (!confirm(`Execute workflow: ${name}?`)) return;
 

server.js

@@ -418,6 +418,16 @@ app.get('/api/executions', authenticateSSO, async (req, res) => {
   }
 });
 
+app.delete('/api/executions/:id', authenticateSSO, async (req, res) => {
+  try {
+    await pool.query('DELETE FROM executions WHERE id = ?', [req.params.id]);
+    broadcast({ type: 'execution_deleted', execution_id: req.params.id });
+    res.json({ success: true });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
 // Health check (no auth required)
 app.get('/health', async (req, res) => {
   try {