fix: stabilize learning path, reliability and legacy Windows builds

Unify beginner syntax while preserving compatibility, repair ownership and parser guards, add verified distribution tooling and VC6 Windows 98 build inputs, and clarify documentation and release status. Preserve DOS build-input line endings and exclude generated binaries/caches.

tools/validate_call_depth_guard.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+"""Verify recursive Claro calls stop with the documented runtime diagnostic."""
+from pathlib import Path
+import subprocess
+import sys
+import tempfile
+
+ROOT = Path(__file__).resolve().parent.parent
+EXPECTED = (
+    "Claro function call depth exceeded the safe limit of 256. "
+    "Simplify the recursion or add a stopping condition."
+)
+SCRIPT = """TEACH loop
+    CALL loop
+ENDTEACH
+TRY
+    CALL loop
+CATCH
+    SAY LASTERROR
+ENDTRY
+"""
+
+
+def main() -> int:
+    binary = ROOT / ("claro.exe" if sys.platform == "win32" else "claro")
+    if not binary.exists():
+        print(f"FAIL: build Claro first; missing {binary}")
+        return 1
+    with tempfile.TemporaryDirectory(prefix="claro-call-depth-") as tmp:
+        program = Path(tmp) / "recursive.claro"
+        program.write_text(SCRIPT, encoding="utf-8")
+        run = subprocess.run([str(binary), str(program)], cwd=ROOT, text=True,
+                             capture_output=True, timeout=30)
+    output = run.stdout + run.stderr
+    if EXPECTED not in output:
+        print("FAIL: recursion did not produce the documented call-depth error")
+        print(output, end="")
+        return 1
+    if run.returncode == 0:
+        print("FAIL: runtime error unexpectedly exited successfully")
+        return 1
+    print("PASS: unbounded recursion stops with the documented call-depth error")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())