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/yargs/index.cjs

@@ -0,0 +1,53 @@
+'use strict';
+// classic singleton yargs API, to use yargs
+// without running as a singleton do:
+// require('yargs/yargs')(process.argv.slice(2))
+const {Yargs, processArgv} = require('./build/index.cjs');
+
+Argv(processArgv.hideBin(process.argv));
+
+module.exports = Argv;
+
+function Argv(processArgs, cwd) {
+  const argv = Yargs(processArgs, cwd, require);
+  singletonify(argv);
+  // TODO(bcoe): warn if argv.parse() or argv.argv is used directly.
+  return argv;
+}
+
+function defineGetter(obj, key, getter) {
+  Object.defineProperty(obj, key, {
+    configurable: true,
+    enumerable: true,
+    get: getter,
+  });
+}
+function lookupGetter(obj, key) {
+  const desc = Object.getOwnPropertyDescriptor(obj, key);
+  if (typeof desc !== 'undefined') {
+    return desc.get;
+  }
+}
+
+/*  Hack an instance of Argv with process.argv into Argv
+    so people can do
+    require('yargs')(['--beeble=1','-z','zizzle']).argv
+    to parse a list of args and
+    require('yargs').argv
+    to get a parsed version of process.argv.
+*/
+function singletonify(inst) {
+  [
+    ...Object.keys(inst),
+    ...Object.getOwnPropertyNames(inst.constructor.prototype),
+  ].forEach(key => {
+    if (key === 'argv') {
+      defineGetter(Argv, key, lookupGetter(inst, key));
+    } else if (typeof inst[key] === 'function') {
+      Argv[key] = inst[key].bind(inst);
+    } else {
+      defineGetter(Argv, '$0', () => inst.$0);
+      defineGetter(Argv, 'parsed', () => inst.parsed);
+    }
+  });
+}