- Fix constant wrap-around: Define `BIT_COUNT`, `BITS_PER_WORD`, and
`WORD_COUNT` (fixed typo from `WORLD_COUNT`) as `size_t` rather than
`T` to prevent silent overflows on large bitsets using small integer
types.
- Fix NEON `all()` truncation: Remove the generic `T` cast to correctly
evaluate bounds across the full 64-bit vector lanes.
- Fix non-NEON `count()` overflow: Use a `size_t` accumulator rather
than `T` to prevent overflow when counting >255 bits on `uint8_t`
parameters.
- Fix NEON strict alignment UB: Enforce unconditional `alignas(16)` on
`storage` when `BIT_COUNT` satisfies 128-bit vector multiples, adding
a compile-time `static_assert` to ensure ABI expectations match NEON
load intrinsics.
- Remove dead masking code inside `firstSetBit()`.