3.1.0

Added

• Configurable block-planning limits. Component.max_gap and
  Component.max_span are now overridable per device (class attribute) or
  instance, instead of fixed module constants. A ComponentGroup validates its
  components agree on both.
  • max_gap (default 16, was 8): in gap-based planning (no
    register_ranges), fields within this many addresses share one read. Higher
    means fewer round-trips but more over-reading; lower is safer for devices
    that reject reads of unmapped registers. Ignored when register_ranges is set.
  • max_span (default 125, the Modbus FC03/FC04 per-request ceiling): the
    widest a single block read may be — lower it for a gateway that caps reads
    shorter.

Changed

• The default max_gap increased from 8 to 16, so devices without declared
  register_ranges issue fewer, wider reads by default.