ATC pneumatics in g-code (drop tool / grab tool / release clamp /
engage clamp) are expressed as M100..M103. AuxPreprocessor rewrites
those into (MSG,HOOK:droptool:) etc on file upload + on planner
load + on MDI input, so the Hooks layer (B1) can dispatch them via
registered ATC handlers in Ctrl.
- AuxPreprocessor.py: regex-based file rewriter, idempotent.
- FileHandler: invoke preprocessor on every upload.
- Planner.init: also re-preprocess on load (catches files written
before this version).
- Mach.mdi: same rewrite for ad-hoc MDI input so M101 typed at the
console produces a HOOK message.
- Ctrl: register the four ATC hooks (droptool/grabtool/release/clamp)
with block_unpause + auto_resume so programs using them pause at
the right point and resume cleanly. aux_home retained as a legacy
alias for older preprocessed files.
