The pin crosses libavr's phase-6 close and the guideline sweep behind it;
the example is byte-identical on both chips in both modes.
The port's own sweep found rule 36 in seven places, and the fix had to be
measured rather than applied. Sakamoto's month offsets as a `std::to_array`
local cost **+348 bytes** on a 1480-byte image - an automatic class-type
constant inside a `constexpr` function is given an address and built per
call, which outlined `weekday()` whole and pulled in `__do_copy_data` and
`__udivmodhi4`; `static constexpr` is what folds it, and emits no symbol at
all. The six register buffers cost +4 as `to_array`, which materialises its
argument array before copying where an aggregate initialiser stores each
element as it is computed - so those take CTAD, which counts the extent and
keeps the direct initialisation. Both spellings are rule 36; only one is
free.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>