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/which/bin/node-which

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+var which = require("../")
+if (process.argv.length < 3)
+  usage()
+
+function usage () {
+  console.error('usage: which [-as] program ...')
+  process.exit(1)
+}
+
+var all = false
+var silent = false
+var dashdash = false
+var args = process.argv.slice(2).filter(function (arg) {
+  if (dashdash || !/^-/.test(arg))
+    return true
+
+  if (arg === '--') {
+    dashdash = true
+    return false
+  }
+
+  var flags = arg.substr(1).split('')
+  for (var f = 0; f < flags.length; f++) {
+    var flag = flags[f]
+    switch (flag) {
+      case 's':
+        silent = true
+        break
+      case 'a':
+        all = true
+        break
+      default:
+        console.error('which: illegal option -- ' + flag)
+        usage()
+    }
+  }
+  return false
+})
+
+process.exit(args.reduce(function (pv, current) {
+  try {
+    var f = which.sync(current, { all: all })
+    if (all)
+      f = f.join('\n')
+    if (!silent)
+      console.log(f)
+    return pv;
+  } catch (e) {
+    return 1;
+  }
+}, 0))