* add new example for enhanced file listing

* adapt Pin

* adapt due to clanf format check in line 14

* Adapt further clang findings

* additional intention corrections

* last clang format issues corrected

* case-sensitive, eof line break

* Fix shell variable comparison without $CI present

+ '[' = true ']'
./tests/restyle.sh: line 16: [: =: unary operator expected

vs.

+ '[' '' = true ']'

* Update to clang-format-18

new opt to skip overly eager macro formatting
https://clang.llvm.org/docs/ClangFormatStyleOptions.html#skipmacrodefinitionbody

minor changes between 15 and 18 for ide examples

reference arduino-ide format is still stuck with 15, though
https://github.com/arduino/clang-static-binaries/releases

* Pin clang-format in CI recipe not the script itself

* style

* Update bearssl builder

* Keep bssl stack pointer from confusing yield

implement stack_thunk_yield() which is called within bssl
stack overflow checks for cont would always fail otherwise

abnormal version selection w/ nbsphinx causing us to fall down to 5.x.x
venv install specific versions, fix arguments provided to the sphinx-build