Frontend improvements: safety, UX, and WebSocket handling

- Guard all new Date().toLocaleString() calls with safeDate() to prevent 'Invalid Date'
- Guard escapeHtml() for null/undefined input
- Guard getTimeAgo() for null/NaN dates; add safeDate() and formatElapsed() helpers
- Show elapsed time for running executions in the execution list
- Add status-running CSS pulse animation class to running execution items
- Add explicit executions_bulk_deleted WebSocket handler
- clearCompletedExecutions() uses new bulk DELETE endpoint instead of N individual requests
- switchTab() persists active tab to localStorage; init restores it on load
- refreshData() updates lastRefreshed timestamp in header
- Add Ctrl+Enter shortcut for quick command form
- Wrap rerunCommand worker_id with escapeHtml() to prevent XSS

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/index.html

@@ -15,6 +15,9 @@
             --terminal-green: #00ff41;
             --terminal-amber: #ffb000;
             --terminal-cyan: #00ffff;
+            --terminal-red: #ff4444;
+            --bg-terminal: #001a00;
+            --bg-terminal-border: #003300;
             --text-primary: #00ff41;
             --text-secondary: #00cc33;
             --text-muted: #008822;
@@ -40,6 +43,7 @@
             --glow-green-intense: 0 0 8px #00ff41, 0 0 16px #00ff41, 0 0 24px #00ff41, 0 0 32px rgba(0, 255, 65, 0.5);
             --glow-amber: 0 0 5px #ffb000, 0 0 10px #ffb000, 0 0 15px #ffb000;
             --glow-amber-intense: 0 0 8px #ffb000, 0 0 16px #ffb000, 0 0 24px #ffb000;
+            --glow-red: 0 0 5px #ff4444, 0 0 10px #ff4444;
         }
 
         * { margin: 0; padding: 0; box-sizing: border-box; }
@@ -72,6 +76,7 @@
             pointer-events: none;
             z-index: 9999;
             animation: scanline 8s linear infinite;
+            will-change: transform;
         }
 
         @keyframes scanline {
@@ -361,7 +366,12 @@
         button::after { content: ' ]'; flex-shrink: 0; }
         /* Suppress bracket pseudo-elements for tab/nav buttons and inline-styled sub-tabs */
         button.tab::before, button.tab::after,
-        button[style*="border:none"]::before, button[style*="border:none"]::after { content: none; }
+        button[style*="border:none"]::before, button[style*="border:none"]::after,
+        button[style*="border: none"]::before, button[style*="border: none"]::after,
+        button[style*="flex:0"]::before, button[style*="flex:0"]::after,
+        button[style*="flex: 0"]::before, button[style*="flex: 0"]::after,
+        button[style*="flex:1"]::before, button[style*="flex:1"]::after,
+        button[style*="flex: 1"]::before, button[style*="flex: 1"]::after { content: none; }
         button:hover {
             background: rgba(0, 255, 65, 0.15);
             color: var(--terminal-amber);
@@ -466,7 +476,7 @@
             border-radius: 0;
             max-width: 600px;
             width: 90%;
-            max-height: 80vh;
+            max-height: 85vh;
             overflow-y: auto;
             box-shadow: 0 0 30px rgba(0, 255, 65, 0.3);
             position: relative;
@@ -624,7 +634,7 @@
         }
 
         .log-entry.failed {
-            border-left-color: #ff4444;
+            border-left-color: var(--terminal-red);
         }
 
         .log-timestamp {
@@ -642,8 +652,8 @@
         }
 
         .log-entry.failed .log-title {
-            color: #ff4444;
+            color: var(--terminal-red);
-            text-shadow: 0 0 5px #ff4444;
+            text-shadow: var(--glow-red);
         }
 
         .log-details {
@@ -662,8 +672,8 @@
         }
 
         .log-output {
-            background: #0a0a0a;
+            background: var(--bg-primary);
-            border: 1px solid #003300;
+            border: 1px solid var(--bg-terminal-border);
             padding: 10px;
             margin: 6px 0;
             color: var(--terminal-green);
@@ -675,14 +685,14 @@
         }
 
         .log-error {
-            color: #ff6666;
+            color: var(--terminal-red);
             border-color: #330000;
         }
 
         .log-entry code {
-            background: #001a00;
+            background: var(--bg-terminal);
             padding: 2px 6px;
-            border: 1px solid #003300;
+            border: 1px solid var(--bg-terminal-border);
             color: var(--terminal-green);
             font-family: var(--font-mono);
         }
@@ -699,15 +709,15 @@
 
         .worker-stats span {
             padding: 2px 6px;
-            background: #001a00;
+            background: var(--bg-terminal);
-            border: 1px solid #003300;
+            border: 1px solid var(--bg-terminal-border);
         }
 
         .worker-metadata {
             margin-top: 12px;
             padding: 10px;
-            background: #001a00;
+            background: var(--bg-terminal);
-            border: 1px solid #003300;
+            border: 1px solid var(--bg-terminal-border);
             font-family: var(--font-mono);
             font-size: 0.85em;
         }
@@ -743,18 +753,18 @@
         }
 
         .execution-item:hover {
-            background: #001a00;
+            background: var(--bg-terminal);
             border-left-width: 5px;
             transform: translateX(3px);
         }
 
         .worker-item:hover {
-            background: #001a00;
+            background: var(--bg-terminal);
             border-left-width: 5px;
         }
 
         .workflow-item:hover {
-            background: #001a00;
+            background: var(--bg-terminal);
             border-left-width: 5px;
         }
 
@@ -768,6 +778,15 @@
             50% { opacity: 1; }
         }
 
+        /* Running execution pulse */
+        .execution-item.status-running {
+            animation: exec-running-pulse 2s ease-in-out infinite;
+        }
+        @keyframes exec-running-pulse {
+            0%, 100% { border-color: var(--terminal-green); }
+            50% { border-color: var(--status-running); box-shadow: 0 0 8px rgba(255,193,7,0.35); }
+        }
+
         /* Success/Error message animations */
         @keyframes slide-in {
             from {
@@ -792,8 +811,11 @@
                 <h1>⚡ PULSE</h1>
                 <p>Pipelined Unified Logic & Server Engine</p>
             </div>
-            <div class="user-info" id="userInfo">
+            <div style="text-align:right;">
-                <div class="loading">Loading user...</div>
+                <div class="user-info" id="userInfo">
+                    <div class="loading">Loading user...</div>
+                </div>
+                <div id="lastRefreshed" style="font-size:0.72em;color:var(--text-muted);font-family:var(--font-mono);margin-top:4px;"></div>
             </div>
         </div>
 
@@ -1263,7 +1285,7 @@
                         <div class="workflow-item">
                             <div class="workflow-name">${w.name}${paramBadge(def)}</div>
                             <div class="workflow-desc">${w.description || 'No description'}</div>
-                            <div class="timestamp">Created by ${w.created_by || 'Unknown'} on ${new Date(w.created_at).toLocaleString()}</div>
+                            <div class="timestamp">Created by ${w.created_by || 'Unknown'} on ${safeDate(w.created_at)?.toLocaleString() ?? 'N/A'}</div>
                             <div style="margin-top: 10px;">
                                 <button onclick="executeWorkflow('${w.id}')">▶️ Execute</button>
                                 ${currentUser && currentUser.isAdmin ?
@@ -1304,8 +1326,8 @@
                             scheduleDesc = `Cron: ${s.schedule_value}`;
                         }
 
-                        const nextRun = s.next_run ? new Date(s.next_run).toLocaleString() : 'Not scheduled';
+                        const nextRun = safeDate(s.next_run)?.toLocaleString() ?? 'Not scheduled';
-                        const lastRun = s.last_run ? new Date(s.last_run).toLocaleString() : 'Never';
+                        const lastRun = safeDate(s.last_run)?.toLocaleString() ?? 'Never';
 
                         return `
                             <div class="workflow-item" style="opacity: ${s.enabled ? 1 : 0.6};">
@@ -1497,7 +1519,7 @@
                             <div class="execution-item" onclick="viewExecution('${e.id}')">
                                 <span class="status ${e.status}">${e.status}</span>
                                 <strong>${e.workflow_name || '[Quick Command]'}</strong>
-                                <div class="timestamp">by ${e.started_by} at ${new Date(e.started_at).toLocaleString()}</div>
+                                <div class="timestamp">by ${e.started_by} at ${safeDate(e.started_at)?.toLocaleString() ?? 'N/A'}</div>
                             </div>
                         `).join('');
                     document.getElementById('dashExecutions').innerHTML = dashHtml;
@@ -1615,14 +1637,15 @@
                     const clickHandler = compareMode ? `toggleExecutionSelection('${e.id}')` : `viewExecution('${e.id}')`;
                     const selectedStyle = isSelected ? 'background: rgba(255, 176, 0, 0.2); border-left-width: 5px; border-left-color: var(--terminal-amber);' : '';
 
+                    const elapsed = e.status === 'running' ? ` • ${formatElapsed(e.started_at)}` : '';
                     return `
-                        <div class="execution-item" onclick="${clickHandler}" style="${selectedStyle} cursor: pointer;">
+                        <div class="execution-item${e.status === 'running' ? ' status-running' : ''}" onclick="${clickHandler}" style="${selectedStyle} cursor: pointer;">
                             ${compareMode && isSelected ? '<span style="color: var(--terminal-amber); margin-right: 8px;">✓</span>' : ''}
                             <span class="status ${e.status}">${e.status}</span>
                             <strong>${e.workflow_name || '[Quick Command]'}</strong>
                             <div class="timestamp">
-                                Started by ${e.started_by} at ${new Date(e.started_at).toLocaleString()}
+                                Started by ${e.started_by} at ${safeDate(e.started_at)?.toLocaleString() ?? 'N/A'}
-                                ${e.completed_at ? ` • Completed at ${new Date(e.completed_at).toLocaleString()}` : ''}
+                                ${e.completed_at ? ` • Completed at ${safeDate(e.completed_at)?.toLocaleString() ?? 'N/A'}` : elapsed}
                             </div>
                         </div>
                     `;
@@ -1737,7 +1760,7 @@
                                     <tr style="border-bottom: 1px solid #003300;">
                                         <td style="padding: 8px; color: var(--terminal-green);">Execution ${idx + 1}</td>
                                         <td style="padding: 8px;"><span class="status ${exec.status}" style="font-size: 0.85em;">${exec.status}</span></td>
-                                        <td style="padding: 8px; color: var(--terminal-green);">${new Date(exec.started_at).toLocaleString()}</td>
+                                        <td style="padding: 8px; color: var(--terminal-green);">${safeDate(exec.started_at)?.toLocaleString() ?? 'N/A'}</td>
                                         <td style="padding: 8px; color: var(--terminal-green);">${duration}</td>
                                     </tr>
                                 `;
@@ -1853,24 +1876,14 @@
             if (!confirm('Delete all completed and failed executions?')) return;
 
             try {
-                const response = await fetch('/api/executions?limit=9999'); // Get all executions
+                const response = await fetch('/api/executions/completed', { method: 'DELETE' });
-                const data = await response.json();
+                if (!response.ok) {
-                const executions = data.executions || data; // Handle new pagination format
+                    const err = await response.json().catch(() => ({}));
-
+                    showTerminalNotification(err.error || 'Failed to delete executions', 'error');
-                const toDelete = executions.filter(e => e.status === 'completed' || e.status === 'failed');
-
-                if (toDelete.length === 0) {
-                    alert('No completed or failed executions to delete');
                     return;
                 }
-
+                const data = await response.json();
-                let deleted = 0;
+                showTerminalNotification(`Deleted ${data.deleted} execution(s)`, 'success');
-                for (const execution of toDelete) {
-                    const deleteResponse = await fetch(`/api/executions/${execution.id}`, { method: 'DELETE' });
-                    if (deleteResponse.ok) deleted++;
-                }
-
-                showTerminalNotification(`Deleted ${deleted} execution(s)`, 'success');
                 refreshData();
             } catch (error) {
                 console.error('Error clearing executions:', error);
@@ -1970,8 +1983,8 @@
                 
                 let html = `
                     <div><strong>Status:</strong> <span class="status ${execution.status}">${execution.status}</span></div>
-                    <div><strong>Started:</strong> ${new Date(execution.started_at).toLocaleString()}</div>
+                    <div><strong>Started:</strong> ${safeDate(execution.started_at)?.toLocaleString() ?? 'N/A'}</div>
-                    ${execution.completed_at ? `<div><strong>Completed:</strong> ${new Date(execution.completed_at).toLocaleString()}</div>` : ''}
+                    ${execution.completed_at ? `<div><strong>Completed:</strong> ${safeDate(execution.completed_at)?.toLocaleString() ?? 'N/A'}</div>` : ''}
                     <div><strong>Started by:</strong> ${execution.started_by}</div>
                 `;
                 
@@ -2015,7 +2028,7 @@
                 // Re-run button (only for quick commands with command in logs)
                 const commandLog = execution.logs?.find(l => l.action === 'command_sent');
                 if (commandLog && commandLog.command) {
-                    html += `<button onclick="rerunCommand('${escapeHtml(commandLog.command)}', '${commandLog.worker_id}')">🔄 Re-run Command</button>`;
+                    html += `<button onclick="rerunCommand('${escapeHtml(commandLog.command)}', '${escapeHtml(commandLog.worker_id || '')}')">🔄 Re-run Command</button>`;
                 }
 
                 // Download logs button
@@ -2264,8 +2277,9 @@
         }
 
         function escapeHtml(text) {
+            if (text == null) return '';
             const div = document.createElement('div');
-            div.textContent = text;
+            div.textContent = String(text);
             return div.innerHTML;
         }
 
@@ -2288,7 +2302,9 @@
         }
 
         function getTimeAgo(date) {
+            if (!date || isNaN(date)) return 'N/A';
             const seconds = Math.floor((new Date() - date) / 1000);
+            if (seconds < 0) return 'just now';
             if (seconds < 60) return `${seconds}s ago`;
             const minutes = Math.floor(seconds / 60);
             if (minutes < 60) return `${minutes}m ago`;
@@ -2298,6 +2314,22 @@
             return `${days}d ago`;
         }
 
+        function safeDate(val) {
+            if (!val) return null;
+            const d = new Date(val);
+            return isNaN(d) ? null : d;
+        }
+
+        function formatElapsed(startedAt) {
+            const start = safeDate(startedAt);
+            if (!start) return '';
+            const secs = Math.floor((Date.now() - start) / 1000);
+            if (secs < 60) return `${secs}s`;
+            const mins = Math.floor(secs / 60);
+            if (mins < 60) return `${mins}m ${secs % 60}s`;
+            return `${Math.floor(mins / 60)}h ${mins % 60}m`;
+        }
+
         async function rerunCommand(command, workerId) {
             if (!confirm(`Re-run command: ${command}?`)) return;
 
@@ -2431,7 +2463,7 @@
                 const html = history.map((item, index) => `
                     <div class="history-item" onclick="useHistoryCommand(${index})" style="cursor: pointer; padding: 12px; margin: 8px 0; background: #001a00; border: 1px solid #003300; border-left: 3px solid var(--terminal-amber);">
                         <div style="color: var(--terminal-green); font-family: var(--font-mono); margin-bottom: 4px;"><code>${escapeHtml(item.command)}</code></div>
-                        <div style="color: #666; font-size: 0.85em;">${new Date(item.timestamp).toLocaleString()} - ${item.worker}</div>
+                        <div style="color: #666; font-size: 0.85em;">${safeDate(item.timestamp)?.toLocaleString() ?? 'N/A'} - ${item.worker}</div>
                     </div>
                 `).join('');
                 document.getElementById('historyList').innerHTML = html;
@@ -2800,37 +2832,24 @@
             document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
             document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
 
-            // Find the button by its onclick attribute rather than relying on bare `event`
             const tabBtn = document.querySelector(`.tab[onclick*="'${tabName}'"]`);
             if (tabBtn) tabBtn.classList.add('active');
             const tabContent = document.getElementById(tabName);
             if (tabContent) tabContent.classList.add('active');
+
+            // Persist active tab across page loads
+            try { localStorage.setItem('pulse_activeTab', tabName); } catch {}
         }
 
         async function refreshData() {
-            try {
+            try { await loadWorkers(); } catch (e) { console.error('Error loading workers:', e); }
-                await loadWorkers();
+            try { await loadWorkflows(); } catch (e) { console.error('Error loading workflows:', e); }
-            } catch (e) {
+            try { await loadExecutions(); } catch (e) { console.error('Error loading executions:', e); }
-                console.error('Error loading workers:', e);
+            try { await loadSchedules(); } catch (e) { console.error('Error loading schedules:', e); }
-            }
 
-            try {
+            // Update "last refreshed" indicator
-                await loadWorkflows();
+            const el = document.getElementById('lastRefreshed');
-            } catch (e) {
+            if (el) el.textContent = `Refreshed: ${new Date().toLocaleTimeString()}`;
-                console.error('Error loading workflows:', e);
-            }
-
-            try {
-                await loadExecutions();
-            } catch (e) {
-                console.error('Error loading executions:', e);
-            }
-
-            try {
-                await loadSchedules();
-            } catch (e) {
-                console.error('Error loading schedules:', e);
-            }
         }
 
         // Terminal beep sound (Web Audio API)
@@ -2992,8 +3011,12 @@
                     loadExecutions();
                 }
 
+                if (data.type === 'executions_bulk_deleted') {
+                    loadExecutions();
+                }
+
                     // Generic refresh for other message types
-                    if (!['command_result', 'workflow_result', 'worker_update', 'execution_started', 'execution_status', 'workflow_created', 'workflow_deleted', 'workflow_updated', 'execution_prompt'].includes(data.type)) {
+                    if (!['command_result', 'workflow_result', 'worker_update', 'execution_started', 'execution_status', 'workflow_created', 'workflow_deleted', 'workflow_updated', 'execution_prompt', 'executions_bulk_deleted'].includes(data.type)) {
                         refreshData();
                     }
                 } catch (error) {
@@ -3026,12 +3049,29 @@
         // Initialize
         loadUser().then((success) => {
             if (success) {
+                // Restore last-active tab
+                try {
+                    const saved = localStorage.getItem('pulse_activeTab');
+                    if (saved) switchTab(saved);
+                } catch {}
+
                 setExecutionView(executionView);
                 refreshData();
                 connectWebSocket();
                 setInterval(refreshData, 30000);
             }
         });
+
+        // Ctrl+Enter submits the quick command form
+        document.addEventListener('keydown', (e) => {
+            if ((e.ctrlKey || e.metaKey) && e.key === 'Enter') {
+                const activeTab = document.querySelector('.tab-content.active');
+                if (activeTab && activeTab.id === 'quickcommand') {
+                    e.preventDefault();
+                    executeQuickCommand();
+                }
+            }
+        });
     </script>
 
     <!-- Terminal Boot Sequence -->

server.js

@@ -33,6 +33,58 @@ const executionLimiter = rateLimit({
 });
 app.use('/api/', apiLimiter);
 
+// Named constants for timeouts and limits
+const PROMPT_TIMEOUT_MS        = 60 * 60 * 1000;   // 60 min — how long a prompt waits for user input
+const COMMAND_TIMEOUT_MS       = 120_000;           // 2 min  — workflow step command timeout
+const QUICK_CMD_TIMEOUT_MS     = 60_000;            // 1 min  — quick/direct/gandalf command timeout
+const WEBHOOK_TIMEOUT_MS       = 10_000;            // 10 s   — outbound webhook HTTP timeout
+const WAIT_STEP_MAX_MS         = 24 * 60 * 60_000; // 24 h   — cap on workflow wait step
+const GOTO_MAX_VISITS          = 100;               // max times a step may be revisited via goto
+const WORKER_STALE_MINUTES     = 5;                 // minutes before a worker is marked offline
+const SERVER_VERSION           = '1.0.0';
+
+// Request logging middleware
+app.use((req, res, next) => {
+  const start = Date.now();
+  res.on('finish', () => {
+    console.log(`[HTTP] ${req.method} ${req.path} ${res.statusCode} ${Date.now() - start}ms`);
+  });
+  next();
+});
+
+// Content-Type guard for JSON endpoints
+function requireJSON(req, res, next) {
+  const ct = req.headers['content-type'] || '';
+  if (!ct.includes('application/json')) {
+    return res.status(415).json({ error: 'Content-Type must be application/json' });
+  }
+  next();
+}
+
+// Validate and parse a webhook URL; returns { ok, url, reason }
+function validateWebhookUrl(raw) {
+  if (!raw) return { ok: true, url: null };
+  let url;
+  try { url = new URL(raw); } catch { return { ok: false, reason: 'Invalid URL format' }; }
+  if (!['http:', 'https:'].includes(url.protocol)) {
+    return { ok: false, reason: 'Webhook URL must use http or https' };
+  }
+  const host = url.hostname.toLowerCase();
+  if (
+    host === 'localhost' ||
+    host === '::1' ||
+    /^127\./.test(host) ||
+    /^10\./.test(host) ||
+    /^192\.168\./.test(host) ||
+    /^172\.(1[6-9]|2\d|3[01])\./.test(host) ||
+    /^169\.254\./.test(host) ||
+    /^fe80:/i.test(host)
+  ) {
+    return { ok: false, reason: 'Webhook URL must not point to a private/internal address' };
+  }
+  return { ok: true, url };
+}
+
 // Database pool
 const pool = mysql.createPool({
   host: process.env.DB_HOST,
@@ -198,9 +250,15 @@ async function processScheduledCommands() {
       console.log(`[Scheduler] Running scheduled command: ${schedule.name}`);
 
       // Handle both string (raw SQL) and object (auto-parsed by MySQL2 JSON column)
-      const workerIds = typeof schedule.worker_ids === 'string'
+      let workerIds;
-        ? JSON.parse(schedule.worker_ids)
+      try {
-        : schedule.worker_ids;
+        workerIds = typeof schedule.worker_ids === 'string'
+          ? JSON.parse(schedule.worker_ids)
+          : schedule.worker_ids;
+      } catch {
+        console.error(`[Scheduler] Invalid worker_ids JSON for "${schedule.name}" — skipping`);
+        continue;
+      }
 
       // Execute command on each worker
       for (const workerId of workerIds) {
@@ -226,7 +284,7 @@ async function processScheduledCommands() {
             execution_id: executionId,
             command: schedule.command,
             worker_id: workerId,
-            timeout: 300000 // 5 minute timeout for scheduled commands
+            timeout: 5 * 60_000 // SCHEDULED_CMD_TIMEOUT
           }));
 
           broadcast({ type: 'execution_started', execution_id: executionId, workflow_id: null });
@@ -286,6 +344,25 @@ setInterval(processScheduledCommands, 60 * 1000);
 // Initial run on startup
 setTimeout(processScheduledCommands, 5000);
 
+// Mark workers offline when their heartbeat goes stale
+async function markStaleWorkersOffline() {
+  try {
+    const [stale] = await pool.query(
+      `SELECT id FROM workers WHERE status = 'online'
+       AND last_heartbeat < DATE_SUB(NOW(), INTERVAL ? MINUTE)`,
+      [WORKER_STALE_MINUTES]
+    );
+    for (const w of stale) {
+      await pool.query(`UPDATE workers SET status='offline' WHERE id=?`, [w.id]);
+      broadcast({ type: 'worker_update', worker_id: w.id, status: 'offline' });
+      console.log(`[Worker] Marked stale worker ${w.id} offline`);
+    }
+  } catch (error) {
+    console.error('[Worker] Stale check error:', error);
+  }
+}
+setInterval(markStaleWorkersOffline, 60_000);
+
 // WebSocket connections
 const browserClients = new Set(); // Browser UI connections
 const workerClients = new Set();  // Worker agent connections
@@ -431,12 +508,14 @@ wss.on('connection', (ws) => {
       }
 
       if (message.type === 'pong') {
-        // Handle worker pong response
+        // Use the DB worker ID stored on connect; fall back to message payload
-        const { worker_id } = message;
+        const dbId = ws.dbWorkerId || message.worker_id;
-        await pool.query(
+        if (dbId) {
-          `UPDATE workers SET last_heartbeat=NOW() WHERE id=?`,
+          await pool.query(
-          [worker_id]
+            `UPDATE workers SET last_heartbeat=NOW() WHERE id=?`,
-        );
+            [dbId]
+          );
+        }
       }
 
     } catch (error) {
@@ -447,7 +526,6 @@ wss.on('connection', (ws) => {
   ws.on('close', () => {
     browserClients.delete(ws);
     workerClients.delete(ws);
-    // Remove worker from workers map when disconnected (both runtime and db IDs)
     if (ws.workerId) {
       workers.delete(ws.workerId);
       console.log(`Worker ${ws.workerId} (runtime ID) disconnected`);
@@ -455,6 +533,10 @@ wss.on('connection', (ws) => {
     if (ws.dbWorkerId) {
       workers.delete(ws.dbWorkerId);
       console.log(`Worker ${ws.dbWorkerId} (database ID) disconnected`);
+      // Mark worker offline in DB
+      pool.query(`UPDATE workers SET status='offline' WHERE id=?`, [ws.dbWorkerId])
+        .then(() => broadcast({ type: 'worker_update', worker_id: ws.dbWorkerId, status: 'offline' }))
+        .catch(err => console.error('[Worker] Failed to mark worker offline:', err));
     }
   });
 });
@@ -520,6 +602,12 @@ async function fireWebhook(executionId, status) {
   if (!rows.length || !rows[0].webhook_url) return;
 
   const exec = rows[0];
+  const { ok, url, reason } = validateWebhookUrl(exec.webhook_url);
+  if (!ok) {
+    console.warn(`[Webhook] Skipping invalid stored URL for execution ${executionId}: ${reason}`);
+    return;
+  }
+
   const payload = {
     execution_id: executionId,
     workflow_id: exec.workflow_id,
@@ -531,15 +619,12 @@ async function fireWebhook(executionId, status) {
     timestamp: new Date().toISOString()
   };
 
-  const url = new URL(exec.webhook_url);
+  const response = await fetch(exec.webhook_url, {
-  const body = JSON.stringify(payload);
-  const options = {
     method: 'POST',
-    headers: { 'Content-Type': 'application/json', 'User-Agent': 'PULSE-Webhook/1.0' }
+    headers: { 'Content-Type': 'application/json', 'User-Agent': 'PULSE-Webhook/1.0' },
-  };
+    body: JSON.stringify(payload),
-
+    signal: AbortSignal.timeout(WEBHOOK_TIMEOUT_MS)
-  // Use native fetch (Node 18+)
+  });
-  const response = await fetch(exec.webhook_url, { ...options, body, signal: AbortSignal.timeout(10000) });
   console.log(`[Webhook] ${url.hostname} responded ${response.status} for execution ${executionId}`);
 }
 
@@ -660,8 +745,20 @@ async function executeWorkflowSteps(executionId, workflowId, definition, usernam
     steps.forEach((step, i) => { if (step.id) stepIdMap.set(step.id, i); });
 
     let currentIndex = 0;
+    const stepVisits = new Array(steps.length).fill(0);
 
     while (currentIndex < steps.length) {
+      // Detect goto infinite loops
+      stepVisits[currentIndex] = (stepVisits[currentIndex] || 0) + 1;
+      if (stepVisits[currentIndex] > GOTO_MAX_VISITS) {
+        await addExecutionLog(executionId, {
+          action: 'workflow_error',
+          error: `Infinite loop detected at step ${currentIndex + 1} (visited ${stepVisits[currentIndex]} times)`,
+          timestamp: new Date().toISOString()
+        });
+        await updateExecutionStatus(executionId, 'failed');
+        return;
+      }
       // Enforce global execution timeout
       if (Date.now() > executionDeadline) {
         await addExecutionLog(executionId, {
@@ -723,7 +820,9 @@ async function executeWorkflowSteps(executionId, workflowId, definition, usernam
         }
 
       } else if (step.type === 'wait') {
-        const ms = (step.duration || 5) * 1000;
+        let ms = parseFloat(step.duration || 5) * 1000;
+        if (isNaN(ms) || ms < 0) ms = 5000;
+        if (ms > WAIT_STEP_MAX_MS) ms = WAIT_STEP_MAX_MS;
         await addExecutionLog(executionId, {
           step: currentIndex + 1, action: 'waiting', duration_ms: ms,
           timestamp: new Date().toISOString()
@@ -795,12 +894,15 @@ async function executePromptStep(executionId, step, stepNumber) {
       _executionPrompts.delete(executionId);
       console.warn(`[Workflow] Prompt timed out for execution ${executionId}`);
       resolve(null);
-    }, 60 * 60 * 1000); // 60 minute timeout
+    }, PROMPT_TIMEOUT_MS);
 
-    _executionPrompts.set(executionId, (response) => {
+    _executionPrompts.set(executionId, {
-      clearTimeout(timer);
+      resolve: (response) => {
-      _executionPrompts.delete(executionId);
+        clearTimeout(timer);
-      resolve(response);
+        _executionPrompts.delete(executionId);
+        resolve(response);
+      },
+      options
     });
   });
 }
@@ -880,11 +982,11 @@ async function executeCommandStep(executionId, step, stepNumber, params = {}) {
         command_id: commandId,
         command: command,
         worker_id: workerId,
-        timeout: 120000 // 2 minute timeout
+        timeout: COMMAND_TIMEOUT_MS
       }));
 
       // Wait for command result (with timeout)
-      const result = await waitForCommandResult(executionId, commandId, 120000);
+      const result = await waitForCommandResult(executionId, commandId, COMMAND_TIMEOUT_MS);
       results.push(result);
 
       if (!result.success) {
@@ -936,7 +1038,8 @@ app.get('/api/workflows', authenticateSSO, async (req, res) => {
     const [rows] = await pool.query('SELECT * FROM workflows ORDER BY created_at DESC');
     res.json(rows);
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[API] GET /api/workflows error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -945,18 +1048,24 @@ app.get('/api/workflows/:id', authenticateSSO, async (req, res) => {
     const [rows] = await pool.query('SELECT * FROM workflows WHERE id = ?', [req.params.id]);
     if (rows.length === 0) return res.status(404).json({ error: 'Not found' });
     const wf = rows[0];
-    res.json({ ...wf, definition: JSON.parse(wf.definition || '{}') });
+    let definition = {};
+    try { definition = JSON.parse(wf.definition || '{}'); } catch { /* corrupt definition — return empty */ }
+    res.json({ ...wf, definition });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[API] GET /api/workflows/:id error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
-app.post('/api/workflows', authenticateSSO, async (req, res) => {
+app.post('/api/workflows', authenticateSSO, requireJSON, async (req, res) => {
   try {
     const { name, description, definition, webhook_url } = req.body;
-    const id = crypto.randomUUID();
+    if (!name || !definition) return res.status(400).json({ error: 'name and definition are required' });
 
-    console.log('[Workflow] Creating workflow:', name);
+    const webhookCheck = validateWebhookUrl(webhook_url);
+    if (!webhookCheck.ok) return res.status(400).json({ error: webhookCheck.reason });
+
+    const id = crypto.randomUUID();
 
     await pool.query(
       'INSERT INTO workflows (id, name, description, definition, webhook_url, created_by) VALUES (?, ?, ?, ?, ?, ?)',
@@ -964,13 +1073,10 @@ app.post('/api/workflows', authenticateSSO, async (req, res) => {
     );
 
     res.json({ id, name, description, definition, webhook_url: webhook_url || null });
-
-    console.log('[Workflow] Broadcasting workflow_created');
     broadcast({ type: 'workflow_created', workflow_id: id });
-    console.log('[Workflow] Broadcast complete');
   } catch (error) {
     console.error('[Workflow] Error creating workflow:', error);
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -985,7 +1091,7 @@ app.delete('/api/workflows/:id', authenticateSSO, async (req, res) => {
     res.json({ success: true });
     broadcast({ type: 'workflow_deleted', workflow_id: req.params.id });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -994,7 +1100,8 @@ app.get('/api/workers', authenticateSSO, async (req, res) => {
     const [rows] = await pool.query('SELECT id, name, status, last_heartbeat, metadata FROM workers ORDER BY name');
     res.json(rows);
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[API] GET /api/workers error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1002,9 +1109,9 @@ app.post('/api/workers/heartbeat', async (req, res) => {
   try {
     const { worker_id, name, metadata } = req.body;
     const apiKey = req.headers['x-api-key'];
-    
+
-    // Verify API key
+    // Verify API key — reject missing or wrong keys
-    if (apiKey !== process.env.WORKER_API_KEY) {
+    if (!apiKey || apiKey !== process.env.WORKER_API_KEY) {
       return res.status(401).json({ error: 'Invalid API key' });
     }
     
@@ -1021,13 +1128,15 @@ app.post('/api/workers/heartbeat', async (req, res) => {
     broadcast({ type: 'worker_update', worker_id, status: 'online' });
     res.json({ success: true });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[Worker] Heartbeat error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
-app.post('/api/executions', executionLimiter, authenticateSSO, async (req, res) => {
+app.post('/api/executions', executionLimiter, authenticateSSO, requireJSON, async (req, res) => {
   try {
     const { workflow_id, params = {}, dry_run = false } = req.body;
+    if (!workflow_id) return res.status(400).json({ error: 'workflow_id is required' });
     const id = crypto.randomUUID();
 
     // Get workflow definition
@@ -1037,7 +1146,12 @@ app.post('/api/executions', executionLimiter, authenticateSSO, async (req, res)
     }
 
     const workflow = workflows[0];
-    const definition = typeof workflow.definition === 'string' ? JSON.parse(workflow.definition) : workflow.definition;
+    let definition;
+    try {
+      definition = typeof workflow.definition === 'string' ? JSON.parse(workflow.definition) : workflow.definition;
+    } catch {
+      return res.status(500).json({ error: 'Workflow definition is corrupt' });
+    }
 
     // Validate required params
     const paramDefs = definition.params || [];
@@ -1069,7 +1183,8 @@ app.post('/api/executions', executionLimiter, authenticateSSO, async (req, res)
 
     res.json({ id, workflow_id, status: 'running', dry_run: !!dry_run });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[Execution] Error starting execution:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1138,7 +1253,21 @@ app.get('/api/executions', authenticateSSO, async (req, res) => {
       hasMore: offset + rows.length < total
     });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
+app.delete('/api/executions/completed', authenticateSSO, async (req, res) => {
+  try {
+    if (!req.user.isAdmin) return res.status(403).json({ error: 'Admin access required' });
+    const [result] = await pool.query(
+      "DELETE FROM executions WHERE status IN ('completed', 'failed')"
+    );
+    broadcast({ type: 'executions_bulk_deleted' });
+    res.json({ success: true, deleted: result.affectedRows });
+  } catch (error) {
+    console.error('[Execution] Bulk delete error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1149,7 +1278,8 @@ app.delete('/api/executions/:id', authenticateSSO, async (req, res) => {
     broadcast({ type: 'execution_deleted', execution_id: req.params.id });
     res.json({ success: true });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[Execution] Error deleting execution:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1180,14 +1310,14 @@ app.post('/api/executions/:id/abort', authenticateSSO, async (req, res) => {
 
     // Unblock any pending prompt so the thread can exit
     const pending = _executionPrompts.get(executionId);
-    if (pending) pending(null);
+    if (pending) pending.resolve(null);
 
     console.log(`[Execution] Execution ${executionId} aborted by ${req.user.username}`);
 
     res.json({ success: true });
   } catch (error) {
     console.error('[Execution] Error aborting execution:', error);
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1197,11 +1327,20 @@ app.post('/api/executions/:id/respond', authenticateSSO, async (req, res) => {
     const { id } = req.params;
     const { response } = req.body;
 
-    if (!response) return res.status(400).json({ error: 'response is required' });
+    if (!response || typeof response !== 'string') {
+      return res.status(400).json({ error: 'response is required' });
+    }
 
     const pending = _executionPrompts.get(id);
     if (!pending) return res.status(404).json({ error: 'No pending prompt for this execution' });
 
+    // Validate response is one of the allowed options
+    if (pending.options && !pending.options.includes(response)) {
+      return res.status(400).json({
+        error: `Invalid response. Allowed values: ${pending.options.join(', ')}`
+      });
+    }
+
     await addExecutionLog(id, {
       action: 'prompt_response', response,
       responded_by: req.user.username,
@@ -1210,15 +1349,15 @@ app.post('/api/executions/:id/respond', authenticateSSO, async (req, res) => {
 
     broadcast({ type: 'prompt_response', execution_id: id, response });
 
-    pending(response);
+    pending.resolve(response);
     res.json({ success: true });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
 // Edit a workflow definition (admin only)
-app.put('/api/workflows/:id', authenticateSSO, async (req, res) => {
+app.put('/api/workflows/:id', authenticateSSO, requireJSON, async (req, res) => {
   try {
     if (!req.user.isAdmin) return res.status(403).json({ error: 'Admin only' });
 
@@ -1227,11 +1366,13 @@ app.put('/api/workflows/:id', authenticateSSO, async (req, res) => {
 
     if (!name || !definition) return res.status(400).json({ error: 'name and definition required' });
 
-    // Validate definition is parseable JSON
+    const webhookCheck = validateWebhookUrl(webhook_url);
+    if (!webhookCheck.ok) return res.status(400).json({ error: webhookCheck.reason });
+
     let defObj;
     try {
       defObj = typeof definition === 'string' ? JSON.parse(definition) : definition;
-    } catch (e) {
+    } catch {
       return res.status(400).json({ error: 'Invalid JSON in definition' });
     }
 
@@ -1245,7 +1386,8 @@ app.put('/api/workflows/:id', authenticateSSO, async (req, res) => {
     broadcast({ type: 'workflow_updated', workflow_id: id });
     res.json({ success: true });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[Workflow] Error updating workflow:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1257,11 +1399,11 @@ app.get('/api/scheduled-commands', authenticateSSO, async (req, res) => {
     );
     res.json(schedules);
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
-app.post('/api/scheduled-commands', authenticateSSO, async (req, res) => {
+app.post('/api/scheduled-commands', authenticateSSO, requireJSON, async (req, res) => {
   try {
     if (!req.user.isAdmin) return res.status(403).json({ error: 'Admin access required' });
     const { name, command, worker_ids, schedule_type, schedule_value } = req.body;
@@ -1270,6 +1412,14 @@ app.post('/api/scheduled-commands', authenticateSSO, async (req, res) => {
       return res.status(400).json({ error: 'Missing required fields' });
     }
 
+    // Validate schedule_value for numeric types
+    if (schedule_type === 'interval' || schedule_type === 'hourly') {
+      const n = parseInt(schedule_value, 10);
+      if (!Number.isInteger(n) || n <= 0) {
+        return res.status(400).json({ error: `schedule_value for type "${schedule_type}" must be a positive integer` });
+      }
+    }
+
     const id = crypto.randomUUID();
     const nextRun = calculateNextRun(schedule_type, schedule_value);
 
@@ -1282,7 +1432,7 @@ app.post('/api/scheduled-commands', authenticateSSO, async (req, res) => {
 
     res.json({ success: true, id });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1301,7 +1451,7 @@ app.put('/api/scheduled-commands/:id/toggle', authenticateSSO, async (req, res)
 
     res.json({ success: true, enabled: newEnabled });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1312,7 +1462,7 @@ app.delete('/api/scheduled-commands/:id', authenticateSSO, async (req, res) => {
     await pool.query('DELETE FROM scheduled_commands WHERE id = ?', [id]);
     res.json({ success: true });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1347,12 +1497,12 @@ app.post('/api/internal/command', authenticateGandalf, async (req, res) => {
       execution_id: executionId,
       command: command,
       worker_id: worker_id,
-      timeout: 60000
+      timeout: QUICK_CMD_TIMEOUT_MS
     }));
 
     res.json({ execution_id: executionId });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1363,12 +1513,32 @@ app.get('/api/internal/executions/:id', authenticateGandalf, async (req, res) =>
       return res.status(404).json({ error: 'Not found' });
     }
     const execution = rows[0];
+    let logs = [];
+    try { logs = JSON.parse(execution.logs || '[]'); } catch { logs = []; }
+    res.json({ ...execution, logs });
+  } catch (error) {
+    console.error('[API] GET /api/internal/executions/:id error:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
+// Detailed health + stats (auth required)
+app.get('/api/health', authenticateSSO, async (req, res) => {
+  try {
+    await pool.query('SELECT 1');
+    const [workerRows] = await pool.query('SELECT status, COUNT(*) as count FROM workers GROUP BY status');
+    const workerCounts = Object.fromEntries(workerRows.map(r => [r.status, Number(r.count)]));
     res.json({
-      ...execution,
+      status: 'ok',
-      logs: JSON.parse(execution.logs || '[]')
+      version: SERVER_VERSION,
+      uptime_seconds: Math.floor(process.uptime()),
+      timestamp: new Date().toISOString(),
+      workers: { online: workerCounts.online || 0, offline: workerCounts.offline || 0 },
+      database: 'connected'
     });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[Health] /api/health error:', error);
+    res.status(500).json({ status: 'error', timestamp: new Date().toISOString() });
   }
 });
 
@@ -1387,7 +1557,7 @@ app.get('/health', async (req, res) => {
       status: 'error', 
       timestamp: new Date().toISOString(),
       database: 'disconnected',
-      error: error.message
+      error: 'Internal server error'
     });
   }
 });
@@ -1401,7 +1571,10 @@ app.get('/api/executions/:id', authenticateSSO, async (req, res) => {
     }
 
     const execution = rows[0];
-    const parsedLogs = typeof execution.logs === 'string' ? JSON.parse(execution.logs || '[]') : (execution.logs || []);
+    let parsedLogs = [];
+    try {
+      parsedLogs = typeof execution.logs === 'string' ? JSON.parse(execution.logs || '[]') : (execution.logs || []);
+    } catch { parsedLogs = []; }
     const waitingForInput = _executionPrompts.has(req.params.id);
     let pendingPrompt = null;
     if (waitingForInput) {
@@ -1420,7 +1593,8 @@ app.get('/api/executions/:id', authenticateSSO, async (req, res) => {
       prompt: pendingPrompt,
     });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    console.error('[API] GET /api/executions/:id error:', error);
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
@@ -1435,14 +1609,17 @@ app.delete('/api/workers/:id', authenticateSSO, async (req, res) => {
     res.json({ success: true });
     broadcast({ type: 'worker_deleted', worker_id: req.params.id });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });
 
 // Send direct command to specific worker
-app.post('/api/workers/:id/command', authenticateSSO, async (req, res) => {
+app.post('/api/workers/:id/command', authenticateSSO, requireJSON, async (req, res) => {
   try {
     const { command } = req.body;
+    if (!command || typeof command !== 'string' || !command.trim()) {
+      return res.status(400).json({ error: 'command is required' });
+    }
     const executionId = crypto.randomUUID();
     const workerId = req.params.id;
 
@@ -1464,7 +1641,7 @@ app.post('/api/workers/:id/command', authenticateSSO, async (req, res) => {
       execution_id: executionId,
       command: command,
       worker_id: workerId,
-      timeout: 60000
+      timeout: QUICK_CMD_TIMEOUT_MS
     };
 
     const workerWs = workers.get(workerId);
@@ -1478,7 +1655,7 @@ app.post('/api/workers/:id/command', authenticateSSO, async (req, res) => {
     broadcast({ type: 'execution_started', execution_id: executionId, workflow_id: null });
     res.json({ success: true, execution_id: executionId });
   } catch (error) {
-    res.status(500).json({ error: error.message });
+    res.status(500).json({ error: 'Internal server error' });
   }
 });