Improve error handling in workflow creation and data loading

- Separated JSON validation from API call error handling
- Changed refreshData() to async with individual try-catch blocks
- Better error messages: "Invalid JSON" vs "Error creating workflow"
- Console.error logging for each data loading function
- Changed success alert to terminal notification
- This will help identify which specific function is failing

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

public/index.html

@@ -2169,9 +2169,15 @@
                 return;
             }
             
+            let definition;
             try {
-                const definition = JSON.parse(definitionText);
+                definition = JSON.parse(definitionText);
+            } catch (error) {
+                alert('Invalid JSON definition: ' + error.message);
+                return;
+            }
 
+            try {
                 const response = await fetch('/api/workflows', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
@@ -2179,15 +2185,15 @@
                 });
 
                 if (response.ok) {
-                    alert('Workflow created!');
                     closeModal('createWorkflowModal');
                     switchTab('workflows');
+                    showTerminalNotification('Workflow created successfully!', 'success');
                     refreshData();
                 } else {
                     alert('Failed to create workflow');
                 }
             } catch (error) {
-                alert('Invalid JSON definition: ' + error.message);
+                alert('Error creating workflow: ' + error.message);
             }
         }
 
@@ -2350,11 +2356,30 @@
             document.getElementById(tabName).classList.add('active');
         }
 
-        function refreshData() {
-            loadWorkers();
-            loadWorkflows();
-            loadExecutions();
-            loadSchedules();
+        async function refreshData() {
+            try {
+                await loadWorkers();
+            } catch (e) {
+                console.error('Error loading workers:', e);
+            }
+
+            try {
+                await loadWorkflows();
+            } catch (e) {
+                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)