The active rewriter for jogs/MDI didn't help anyway because the
continuous-jog buttons send rate-based /api/jog commands to the AVR
and bypass the planner+MDI path entirely. Rather than build out
continuous-jog coupling on the ESP firmware or fake it with browser
ticks, simplify back to:
* Runtime check (Planner.__encode + ExternalAxis motion entry
points) refuses any move that would worsen the Z-A gap. Already
improvement-aware so X/Y jogs and Z-up/A-down recoveries pass.
* File preprocessor (AuxPreprocessor) injects pre-position A
moves into uploaded gcode so well-formed programs run without
operator intervention.
Operator workflow: jog freely down to the safe band; if you need to
go deeper, lower A first (aux jog mm) or use a step-jog MDI like
'G91 G0 Z-10 A-10' that includes the A delta. Programs do the right
thing on their own.