When running discovery multiple times, duplicate Docker bridge interfaces
  and empty host entries were created instead of conflating with existing
  entities.

  Root causes:
  - Interface equality only compared IP + subnet_id, so containers with
    changed IPs (Docker DHCP) were treated as new interfaces
  - Docker discovery didn't include the daemon host's physical interfaces,
    so network discovery couldn't match hosts by MAC or subnet+IP

  Changes:
  - Add MAC address to Interface PartialEq and Hash implementations
  - Include daemon host physical interfaces in Docker discovery temp host

…ap prevention

  Add horizontal compression pass that runs after edge optimization:
  - Subnets with non-horizontal (vertical/mixed) edges are locked in place
  - Unlocked subnets are compressed toward locked ones to minimize empty space
  - Subnets with no locked neighbors compress toward the left edge

  Fix subnet overlap bug in apply_non_overlap_constraint:
  - Previous logic could oscillate between positions when multiple subnets
    wanted the same X coordinate (e.g., docker bridges connecting to same host)
  - New approach generates candidate positions at subnet edges and selects
    the valid non-overlapping position closest to the optimal edge length

  Add SUBNET_PADDING constant (125px) for consistent spacing throughout
  the subnet positioning algorithm.

  - Fix auto reload toggle not persisting across page reloads by adding
    localStorage save/load logic and preventing initial subscription from
    overwriting stored value
  - Align backend default for group_docker_bridges_by_host to true,
    matching the frontend default
  - Hide interface edge labels when both connected nodes are on the same
    subnet to reduce visual clutter

…s an equality key

…s an equality key

…s an equality key