refactor: remove excessive code, move script to app.js

src/js/app.js

@@ -0,0 +1,89 @@
+// Application initialization and event handlers
+
+document.addEventListener('DOMContentLoaded', function () {
+    // Initialize snippet storage and render list
+    initializeSnippetsStorage();
+
+    // Initialize sort controls
+    initializeSortControls();
+
+    // Initialize search controls
+    initializeSearchControls();
+
+    renderSnippetList();
+
+    // Load saved layout
+    loadLayoutFromStorage();
+
+    // Initialize resize functionality
+    initializeResize();
+
+    // Initialize Monaco Editor
+    require.config({ paths: { vs: 'https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.47.0/min/vs' } });
+    require(['vs/editor/editor.main'], async function () {
+        // Fetch Vega-Lite schema for validation
+        let vegaLiteSchema;
+        try {
+            const response = await fetch('https://vega.github.io/schema/vega-lite/v5.json');
+            vegaLiteSchema = await response.json();
+        } catch (error) {
+            vegaLiteSchema = null;
+        }
+
+        // Configure JSON language with schema
+        if (vegaLiteSchema) {
+            monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
+                validate: true,
+                schemas: [{
+                    uri: "https://vega.github.io/schema/vega-lite/v5.json",
+                    fileMatch: ["*"],
+                    schema: vegaLiteSchema
+                }]
+            });
+        }
+
+        // Load Vega libraries before creating editor
+        await loadVegaLibraries();
+
+        // Create the editor
+        editor = monaco.editor.create(document.getElementById('monaco-editor'), {
+            value: JSON.stringify(sampleSpec, null, 2),
+            language: 'json',
+            theme: 'vs-light',
+            fontSize: 12,
+            minimap: { enabled: false },
+            scrollBeyondLastLine: false,
+            automaticLayout: true,
+            wordWrap: 'on',
+            formatOnPaste: true,
+            formatOnType: true
+        });
+
+        // Add debounced auto-render on editor change
+        editor.onDidChangeModelContent(() => {
+            debouncedRender();
+            debouncedAutoSave();
+        });
+
+        // Initial render
+        renderVisualization();
+
+        // Initialize auto-save functionality
+        initializeAutoSave();
+    });
+
+    // Toggle panel buttons
+    document.querySelectorAll('.toggle-btn').forEach(button => {
+        button.addEventListener('click', function () {
+            const panelId = this.id.replace('toggle-', '');
+            togglePanel(panelId);
+        });
+    });
+
+    // Header links - show placeholder
+    document.querySelectorAll('.header-link').forEach(link => {
+        link.addEventListener('click', function () {
+            alert('Coming soon in a future phase!');
+        });
+    });
+});