fix: off-by-one error in binary_count_trailing_zeros for zero input

## Description "The function returns `0` for `a == 0`, but mathematically, trailing zeros in binary representation of 0 are undefined (or conventionally treated as infinite). While `log2(a & -a)` fails for `a=0`, the current fallback to `0` is inconsistent with the documented behavior: `binary_count_trailing_zeros(16)` returns `4`, but `0` has infinitely many trailing zeros — returning `0` is misleading and could cause bugs in algorithms relying on this (e.g., bit manipulation loops expecting correct trailing zero counts)." **Severity**: `high` **File**: `bit_manipulation/binary_count_trailing_zeros.py` ## Expected Behavior This should be handled properly to prevent runtime errors or degraded reliability.