feat: add refactored testdrive-jsui capability with consolidated architecture

Complete integration of refactored testdrive-jsui capability:

## Refactored Architecture
- js/ - All JavaScript source (controls, components, core)
- static/ - CSS, images, templates
- src/testdrive_jsui/ - Python package
- tests/ - Python tests

## Plugin Self-Declaration
- get_plugin_source_dir() - plugin declares own location
- get_asset_paths() - organized asset paths
- No hardcoded discovery logic

## Merged Content
- Baseline UI scaffold (tutorials, LICENSE, INTRODUCTION.md)
- Refactored capability implementation
- Comprehensive documentation

Ready for standalone use or integration with markitect.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

js/tests/test-environment.test.js

@@ -0,0 +1,24 @@
+/**
+ * Environment Test - Verifies Jest setup is working correctly
+ */
+
+describe('Test Environment', () => {
+    test('should have JSDOM environment available', () => {
+        expect(global.document).toBeDefined();
+        expect(global.window).toBeDefined();
+        expect(document.createElement).toBeDefined();
+    });
+
+    test('should be able to create DOM elements', () => {
+        const div = document.createElement('div');
+        div.textContent = 'Test content';
+        expect(div.tagName).toBe('DIV');
+        expect(div.textContent).toBe('Test content');
+    });
+
+    test('should have content container available', () => {
+        const contentEl = document.getElementById('content');
+        expect(contentEl).toBeDefined();
+        expect(contentEl.tagName).toBe('DIV');
+    });
+});