Add Doodle Labs Mesh Rider radio support

[harelb]

Adds parallel support for Doodle Labs Mesh Rider radios alongside the existing Silvus monitoring, since the fleet is transitioning to Doodle Labs hardware. Auto-detects the radio type from topology.yaml, with an optional --radio-type CLI override on fleet-adt4.

New diagnostic scripts (network_diagnostics/scripts):

• doodlelabs_status.sh — standalone CLI equivalent to silvus_status.sh, supporting status/topology/discover/linkstate/battery-watch/radio-config/ ssh commands against the HTTPS/ubus API
• doodlelabs_mesh_viz.py — live force-directed mesh topology visualizer served as a local web dashboard (Python stdlib + vis-on-canvas)

Fleet manager integration (dcist_launch_system):

• New helpers in fleet_helpers.py: get_doodlelabs_link_quality, get_doodlelabs_radio_details, check/add_doodlelabs_route, and get_active_radio_type(topology, override) for dispatch
• get_remote_status now accepts doodlelabs_ips/doodlelabs_creds and emits a neutral '---RADIO---' section (backward-compatible with '---SILVUS---' for older remote machines)
• MonitorScreen refresh/check_zenoh/silvus_detail/check_silvus_routes actions dispatch to the correct API based on active radio type; the F4 detail view renders an RSSI matrix from sta_stats plus batman-adv TQ from mesh_stats; route-check help message now also prints a template command when the LOCAL machine has no radio interface
• New --radio-type {auto,silvus,doodlelabs,none} CLI flag plumbed through TuiContext.radio_type_override; default 'auto' infers from whichever *_radios section is populated

topology.yaml:

• New doodlelabs_radios section with user/password/ip per radio
• Fix typo: sequia -> sequoia in machines and docs