v0.6.1 — speed mode survives Canvas filament switches

Fixed

• CC2: the user's speed mode now survives Canvas filament switches.
  The firmware resets speed_mode to balanced on every mid-print
  switch and leaves it there (verified 2026-07-05: mode stayed reset
  after the switch completed). CC2Printer now snapshots the mode in
  effect when a switch begins and re-applies it once printing resumes —
  regardless of whether the mode was set via pycentauri or the
  touchscreen. Requires enable_control; read-only sessions log the
  reset instead. The restore baseline is debounced (a mode must hold
  15 s to count) because the firmware fires its reset several seconds
  before the head parks — without the debounce, that transient
  poisoned the snapshot. Verified across two hands-free switch cycles
  with journal-logged restores ~3 s after each resume.
• centauri server now surfaces pycentauri's own log lines (speed-mode
  restores, reconnects) in its output — previously only uvicorn's
  loggers were configured and library INFO logs were invisible.