build: add autotools bootstrap skeleton with C23 flags

src/Makefile.am

@@ -0,0 +1,6 @@
+# src/Makefile.am - build the stupidtools binary (C23, strict warnings).
+
+AM_CFLAGS = -std=c23 -Wall -Wextra -Wpedantic
+
+bin_PROGRAMS = stupidtools
+stupidtools_SOURCES = main.c

src/main.c

@@ -0,0 +1,24 @@
+/*
+ * stupidtools - the GNU AutoTools replacement for the moronic.
+ *
+ * Copyright (c) 2026 huntedbytheirs
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Minimal skeleton: reports the version. Real CLI parsing (todo 4)
+ * replaces this stub.
+ */
+
+#include <stdio.h>
+
+/* Must match AC_INIT version in configure.ac (todo 1: 1.0.0). */
+#define STUPIDTOOLS_VERSION "1.0.0"
+
+int
+main(int argc, char **argv)
+{
+	(void)argc;
+	(void)argv;
+
+	printf("stupidtools %s\n", STUPIDTOOLS_VERSION);
+	return 0;
+}