…ndpoints

  This addresses two issues affecting network discovery reliability:

  1. ARP Scan Hang (#374): Network scans hung indefinitely when targets
     didn't respond to ARP requests. The datalink channel was using
     default config with no read_timeout, causing rx.next() to block
     forever. Added 100ms read_timeout to allow deadline checks.

  2. Subnet Misclassification (#374): On Unraid/Proxmox systems where
     the physical LAN uses a bridge interface (br0), subnets were
     incorrectly classified as DockerBridge, causing network discovery
     to skip them.

     Root cause: Docker's macvlan/ipvlan networks (used for container
     LAN access) were being treated the same as bridge networks, and
     the filter logic was backwards - removing host subnets instead of
     Docker subnets when CIDRs overlapped.

     Fixes:
     - Filter Docker networks by driver type: only bridge/overlay are
       DockerBridge, skip macvlan/ipvlan/host
     - Flip filter precedence: host interfaces take priority over
       Docker networks with same CIDR
     - Add br to LAN interface patterns (distinct from br- which
       is Docker's convention)