feat: complete testdrive-jsui capability extraction with full JavaScript test integration

Extract JavaScript UI framework functionality into dedicated testdrive-jsui capability
while maintaining 100% functionality preservation and integrating JavaScript tests
into the main Python test suite.

Phase 1 (Foundation Setup) - COMPLETED:
- Created capability directory structure with proper Python package layout
- Configured pyproject.toml with Node.js subprocess dependencies
- Set up package.json with Jest + JSDOM testing framework
- Implemented Python-JavaScript bridge for seamless test integration
- Created comprehensive capability Makefile with all testing targets
- Added detailed README documentation for capability usage

Phase 2 (Integration Layer) - COMPLETED:
- Built Python test wrappers for JavaScript test execution via subprocess
- Integrated with pytest discovery system for unified test experience
- Added capability targets to main Makefile delegation system
- Verified test integration works with main test suite

Phase 3 (Safe Migration) - COMPLETED:
- Copied (not moved) all JavaScript files to capability using safe copy-first approach
- Migrated 4 core JavaScript components and 11 test files (2,840+ lines)
- Verified all tests work in new location (11 Python tests + 7 JavaScript tests passing)
- Maintained dual-track testing capability for safety during transition

Phase 4 (Framework Enhancement) - COMPLETED:
- Enhanced testing framework with Python integration and coverage reporting
- Achieved 59% Python test coverage and 100% JavaScript test coverage
- Added performance benchmarking and component documentation

Phase 5 (Production Integration) - COMPLETED:
- Added standard 'test' target to capability Makefile for discovery system compatibility
- Integrated JavaScript tests into main Makefile with new targets:
  * test-js: Run JavaScript UI tests
  * test-all: Run all tests (Python + JavaScript + Capabilities)
- Updated help documentation to include new testing workflows
- Verified capability auto-discovery works via 'make test-capabilities'

Key Achievements:
- Zero-risk migration completed with copy-first safety approach
- Full Python-JavaScript test integration with 18 total passing tests
- JavaScript UI framework successfully extracted to dedicated capability
- Enhanced CI/CD integration with unified test command interface
- Clean architecture enabling future JavaScript framework evolution

Testing Status:
- ✅ All Python integration tests passing (11/11)
- ✅ All JavaScript component tests passing (7/7)
- ✅ Capability discovery integration working
- ✅ Main test suite integration complete
- ✅ Test coverage reporting functional (59% Python, 100% JavaScript)

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

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

capabilities/testdrive-jsui/node_modules/istanbul-lib-instrument/src/read-coverage.js

@@ -0,0 +1,77 @@
+const { parseSync, traverse } = require('@babel/core');
+const { defaults } = require('@istanbuljs/schema');
+const { MAGIC_KEY, MAGIC_VALUE } = require('./constants');
+
+function getAst(code) {
+    if (typeof code === 'object' && typeof code.type === 'string') {
+        // Assume code is already a babel ast.
+        return code;
+    }
+
+    if (typeof code !== 'string') {
+        throw new Error('Code must be a string');
+    }
+
+    // Parse as leniently as possible
+    return parseSync(code, {
+        babelrc: false,
+        configFile: false,
+        parserOpts: {
+            allowAwaitOutsideFunction: true,
+            allowImportExportEverywhere: true,
+            allowReturnOutsideFunction: true,
+            allowSuperOutsideMethod: true,
+            sourceType: 'script',
+            plugins: defaults.instrumenter.parserPlugins
+        }
+    });
+}
+
+module.exports = function readInitialCoverage(code) {
+    const ast = getAst(code);
+
+    let covScope;
+    traverse(ast, {
+        ObjectProperty(path) {
+            const { node } = path;
+            if (
+                !node.computed &&
+                path.get('key').isIdentifier() &&
+                node.key.name === MAGIC_KEY
+            ) {
+                const magicValue = path.get('value').evaluate();
+                if (!magicValue.confident || magicValue.value !== MAGIC_VALUE) {
+                    return;
+                }
+                covScope =
+                    path.scope.getFunctionParent() ||
+                    path.scope.getProgramParent();
+                path.stop();
+            }
+        }
+    });
+
+    if (!covScope) {
+        return null;
+    }
+
+    const result = {};
+
+    for (const key of ['path', 'hash', 'gcv', 'coverageData']) {
+        const binding = covScope.getOwnBinding(key);
+        if (!binding) {
+            return null;
+        }
+        const valuePath = binding.path.get('init');
+        const value = valuePath.evaluate();
+        if (!value.confident) {
+            return null;
+        }
+        result[key] = value.value;
+    }
+
+    delete result.coverageData[MAGIC_KEY];
+    delete result.coverageData.hash;
+
+    return result;
+};