Stop using bdwidth while printing, work without it

bdwidth's motion reading stays at 0, its per-reading width compensation
made the flow jump between 77 and 119%, and a USB dropout shut down
Klipper. PRINT_START no longer enables it. _PRINT_CLEANUP,
BLOBIFIER_CHECKED and PURGE_UNTIL_EMPTY only send bdwidth commands when
[bdwidth fila_width_0] exists, and bdwidth_status reports present: False
with neutral values when it is not configured, so the section can be
removed from printer.cfg.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -11,10 +11,10 @@ Voron 2.4 350, Klipper + Moonraker + Mainsail on a Raspberry Pi 4
 5 lanes, Blobifier purge bucket, Beacon (Z homing and probing), Nitehawk-SB
 toolboard (USB), Leviathan mainboard as USB-CAN bridge, bd_pressure
 (load-check firmware, branch `load-check-extension` in
-`D:\Claude\bd_pressure-load-check\bd_pressure`), bdwidth (measures width and
-motion optically with a CCD; its motion reading stays at 0, so it runs width
-only (`ENABLE_WIDTH` in PRINT_START) and the purge check runs with
-`motion_check: False`; clogs and breaks are caught by AFC's buffer fault
+`D:\Claude\bd_pressure-load-check\bd_pressure`), bdwidth (CCD width/motion sensor on USB; switched off: its motion reading
+stays at 0, its width compensation made the flow jump 77-119% and a USB
+dropout once shut down Klipper. The macros work with or without
+`[bdwidth fila_width_0]`; clogs and breaks are caught by AFC's buffer fault
 detection, `filament_error_sensitivity`), iHeater chamber heater.
 
 ## Working with the printer