escape parentheses and other special characters in tab completion

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

main.go

@@ -963,11 +963,13 @@ func currentWord(s string) (word string, start int, quote byte) {
 	return b.String(), start, quote
 }
 
-// escapeWord escapes characters that would otherwise be interpreted by shlex
+// escapeWord escapes characters that would otherwise be interpreted by the
+// shell. # and ~ are only special at the start of a word, so they are only
+// escaped at the start of s.
 func escapeWord(s string) string {
 	var b strings.Builder
-	for _, r := range s {
-		if strings.ContainsRune(" \t\\'\";|&<>*?[${", r) {
+	for i, r := range s {
+		if strings.ContainsRune(" \t\\'\"`;|&<>()*?[]{}$!", r) || (i == 0 && (r == '#' || r == '~')) {
 			b.WriteByte('\\')
 		}
 		b.WriteRune(r)