feat(cmd): GOOS-aware headers, audit battery shapes and semicolon spacing

Assisted-by: GLM 5.3 Flash

format/format.go

@@ -241,6 +241,13 @@ func renderInstr(line []token.Token, width int) string {
 	if line[0].Kind != token.Ident {
 		return "\t" + mnem + " " + ops
 	}
+	// A statement separator belongs to the statement it ends: when the
+	// operands open with a ';', the alignment padding would land between
+	// the mnemonic and its own separator (REP  ; MOVSQ), so such a line
+	// renders with a single space whatever the function's width.
+	if strings.HasPrefix(ops, ";") {
+		return "\t" + mnem + " " + ops
+	}
 	if width < len(mnem) {
 		width = len(mnem)
 	}