fix(tests): resolve Windows CI test failures (#701)

* fix(tests): skip bash tests on Windows and fix USERPROFILE in resolve-ecc-root

- hooks.test.js: add SKIP_BASH guard for 8 bash-dependent tests
  (detect-project.sh, observe.sh) while keeping 207 Node.js tests running
- resolve-ecc-root.test.js: add USERPROFILE to env overrides in 2
  INLINE_RESOLVE tests so os.homedir() resolves correctly on Windows

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

* fix(tests): handle BOM in shebang stripping and skip worktree tests on Windows

- validators.test.js: replace regex stripShebang with character-code
  approach that handles UTF-8 BOM before shebang line
- detect-project-worktree.test.js: skip entire file on Windows since
  tests invoke bash scripts directly

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Happy <yesreply@happy.engineering>

tests/hooks/detect-project-worktree.test.js

@@ -8,6 +8,12 @@
  * Run with: node tests/hooks/detect-project-worktree.test.js
  */
 
+
+// Skip on Windows — these tests invoke bash scripts directly
+if (process.platform === 'win32') {
+  console.log('Skipping bash-dependent worktree tests on Windows\n');
+  process.exit(0);
+}
 const assert = require('assert');
 const path = require('path');
 const fs = require('fs');