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

[zendy199x]

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.