Set explicit args for install-hook test command

Prevents test flakiness from go test flags being parsed by cobra.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: wesm

cmd/roborev/main_test.go

@@ -435,6 +435,7 @@ func TestInstallHookCmdCreatesHooksDirectory(t *testing.T) {
 
 	// Run install-hook command
 	installCmd := installHookCmd()
+	installCmd.SetArgs([]string{})
 	err := installCmd.Execute()
 
 	if err != nil {