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>

test-documents/sample.md

@@ -0,0 +1,57 @@
+# TestDrive JSUI Sample Document
+
+This is a sample markdown document for testing the TestDrive JavaScript UI plugin.
+
+## Features to Test
+
+### Basic Editing
+- Click any section to edit it
+- Use the save button to download your changes
+- Reset button restores original content
+
+### Control Panels
+- **Contents Control** (Northwest): Document outline and navigation
+- **Status Control** (East): Current document statistics
+- **Debug Control** (Southeast): Development information and logs
+- **Edit Control** (Northeast): Main editing actions
+
+### Markdown Support
+Test various markdown elements:
+
+**Bold text** and *italic text*
+
+> This is a blockquote
+> with multiple lines
+
+```javascript
+// Code blocks with syntax highlighting
+function testFunction() {
+    console.log("Hello from TestDrive JSUI!");
+    return true;
+}
+```
+
+### Lists
+1. Numbered list item one
+2. Numbered list item two
+3. Numbered list item three
+
+- Bullet list item
+- Another bullet item
+  - Nested bullet item
+  - Another nested item
+
+### Tables
+
+| Feature | Status | Notes |
+|---------|--------|--------|
+| Section editing | ✅ Working | Click to edit |
+| Asset loading | ✅ Working | External scripts |
+| Configuration | ✅ Working | JSON interface |
+| Controls | 🚧 Testing | Compass positioning |
+
+### Links and Images
+Visit the [Markitect repository](https://github.com/markitect/markitect) for more information.
+
+---
+*Test document for TestDrive JSUI plugin development*