Fix hook test portability and robustness (#182)

## Summary
- Add `-Encoding UTF8` to `Set-Content` in `pwdCmd` to avoid UTF-16LE on
Windows PowerShell 5.1
- Use exact path comparison on Unix, `EqualFold` only on Windows
- Add `t.Cleanup` safety net for logger restoration in log capture tests
- Fix stale `shellEscape` doc comment to reflect single-quote behavior

## Test plan
- [ ] CI passes on all platforms (Ubuntu, macOS, Windows)

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

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: wesm

internal/daemon/hooks.go

@@ -170,8 +170,8 @@ func interpolate(cmd string, event Event) string {
 }
 
 // shellEscape quotes a value for safe interpolation into a shell command.
-// On Unix, wraps in single quotes with embedded single quotes escaped.
-// On Windows, wraps in double quotes with embedded double quotes escaped.
+// Wraps in single quotes on all platforms, with embedded single quotes escaped.
+// On Windows (PowerShell), '' escapes a literal '. On Unix, uses '"'"'.
 func shellEscape(s string) string {
 	if runtime.GOOS == "windows" {
 		// PowerShell single-quoted strings: only escape is '' for literal '.

internal/daemon/hooks_test.go

@@ -40,7 +40,7 @@ func touchCmd(path string) string {
 // pwdCmd returns a platform-appropriate shell command to write the cwd to a file.
 func pwdCmd(path string) string {
 	if runtime.GOOS == "windows" {
-		return "(Get-Location).Path | Set-Content -NoNewline '" + filepath.ToSlash(path) + "'"
+		return "[IO.File]::WriteAllText('" + filepath.ToSlash(path) + "', (Get-Location).Path)"
 	}
 	return "pwd > " + path
 }
@@ -407,7 +407,11 @@ func TestHookRunnerWorkingDirectory(t *testing.T) {
 					want = w
 				}
 			}
-			if !strings.EqualFold(got, want) {
+			equal := got == want
+			if runtime.GOOS == "windows" {
+				equal = strings.EqualFold(got, want)
+			}
+			if !equal {
 				t.Errorf("hook ran in %q, want %q", got, want)
 			}
 			return
@@ -674,6 +678,7 @@ func TestHandleEventLogsWhenHooksFired(t *testing.T) {
 	var buf bytes.Buffer
 	prevOut := log.Writer()
 	log.SetOutput(&buf)
+	t.Cleanup(func() { log.SetOutput(prevOut) })
 
 	cfg := &config.Config{
 		Hooks: []config.HookConfig{
@@ -710,6 +715,7 @@ func TestHandleEventNoLogWhenNoHooksMatch(t *testing.T) {
 	var buf bytes.Buffer
 	prevOut := log.Writer()
 	log.SetOutput(&buf)
+	t.Cleanup(func() { log.SetOutput(prevOut) })
 
 	cfg := &config.Config{
 		Hooks: []config.HookConfig{