int(None) answers 0 instead of raising TypeError

Found 2026-10-19 compiling sysdash's backend.py (the Vloot fleet monitor's collector). int(read(path)) on a root-only RAPL file got int(None), which answered 0, so the program's except TypeError never ran and the native binary reported a measured 0 J where CPython fell back to the estimate. That's a silent wrong value.

Cause: pyint_v (compiler/builtin/pylib.pas) handed VT_EMPTY to pyvar_to_int, whose None→0 is the deliberate Optional[int] sentinel for coercions. An explicit int() call is not a coercion.

Fix: pyint_v raises CPython's TypeError for VT_EMPTY. pyvar_to_int is unchanged, so the sentinel contract that uforth relies on still holds. float(None) already raised.

Test: test/test_nilpy_int_of_none_raises.npy (four routes: a variant parameter, a None return, the literal, a missing dict.get).