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/exit/test/exit_test.js

@@ -0,0 +1,121 @@
+'use strict';
+
+/*
+  ======== A Handy Little Nodeunit Reference ========
+  https://github.com/caolan/nodeunit
+
+  Test methods:
+    test.expect(numAssertions)
+    test.done()
+  Test assertions:
+    test.ok(value, [message])
+    test.equal(actual, expected, [message])
+    test.notEqual(actual, expected, [message])
+    test.deepEqual(actual, expected, [message])
+    test.notDeepEqual(actual, expected, [message])
+    test.strictEqual(actual, expected, [message])
+    test.notStrictEqual(actual, expected, [message])
+    test.throws(block, [error], [message])
+    test.doesNotThrow(block, [error], [message])
+    test.ifError(value)
+*/
+
+var fs = require('fs');
+var exec = require('child_process').exec;
+
+var _which = require('which').sync;
+function which(command) {
+  try {
+    _which(command);
+    return command;
+  } catch (err) {
+    return false;
+  }
+}
+
+// Look for grep first (any OS). If not found (but on Windows) look for find,
+// which is Windows' horribly crippled grep alternative.
+var grep = which('grep') || process.platform === 'win32' && which('find');
+
+exports['exit'] = {
+  setUp: function(done) {
+    this.origCwd = process.cwd();
+    process.chdir('test/fixtures');
+    done();
+  },
+  tearDown: function(done) {
+    process.chdir(this.origCwd);
+    done();
+  },
+  'grep': function(test) {
+    test.expect(1);
+    // Many unit tests depend on this.
+    test.ok(grep, 'A suitable "grep" or "find" program was not found in the PATH.');
+    test.done();
+  },
+  // The rest of the tests are built dynamically, to keep things sane.
+};
+
+// A few helper functions.
+function normalizeLineEndings(s) {
+  return s.replace(/\r?\n/g, '\n');
+}
+
+// Capture command output, normalizing captured stdout to unix file endings.
+function run(command, callback) {
+  exec(command, function(error, stdout) {
+    callback(error ? error.code : 0, normalizeLineEndings(stdout));
+  });
+}
+
+// Read a fixture file, normalizing file contents to unix file endings.
+function fixture(filename) {
+  return normalizeLineEndings(String(fs.readFileSync(filename)));
+}
+
+function buildTests() {
+  // Build individual unit tests for command output.
+  var counts = [10, 100, 1000];
+  var outputs = [' stdout stderr', ' stdout', ' stderr'];
+  var pipes = ['', ' | ' + grep + ' "std"'];
+  counts.forEach(function(count) {
+    outputs.forEach(function(output) {
+      pipes.forEach(function(pipe) {
+        var command = 'node log.js 0 ' + count + output + ' 2>&1' + pipe;
+        exports['exit']['output (' + command + ')'] = function(test) {
+          test.expect(2);
+          run(command, function(code, actual) {
+            var expected = fixture(count + output.replace(/ /g, '-') + '.txt');
+            // Sometimes, the actual file lines are out of order on Windows.
+            // But since the point of this lib is to drain the buffer and not
+            // guarantee output order, we only test the length.
+            test.equal(actual.length, expected.length, 'should be the same length.');
+            // The "fail" lines in log.js should NOT be output!
+            test.ok(actual.indexOf('fail') === -1, 'should not output after exit is called.');
+            test.done();
+          });
+        };
+      });
+    });
+  });
+
+  // Build individual unit tests for exit codes.
+  var codes = [0, 1, 123];
+  codes.forEach(function(code) {
+    var command = 'node log.js ' + code + ' 10 stdout stderr';
+    exports['exit']['exit code (' + command + ')'] = function(test) {
+      test.expect(1);
+      run(command, function(actual) {
+        // The specified exit code should be passed through.
+        test.equal(actual, code, 'should exit with ' + code + ' error code.');
+        test.done();
+      });
+    };
+  });
+}
+
+// Don't bother building tests if grep wasn't found, otherwise everything will
+// fail and the error will get lost.
+if (grep) {
+  buildTests();
+}