Run 10536 reached pytest but every connect was reset: the simulator died at
import with 'Tkinter is needed' — lib/gui.py calls matplotlib.use("TkAgg")
unconditionally (an explicit use() overrides MPLBACKEND=Agg), and the port
probe passed instantly because it was accepting the localhost forwarders, not
the nodes.
- run_e2e.sh: patch meshtasticator lib/gui.py TkAgg->Agg before boot;
probe readiness on the upstream host (docker daemon) when forwards are
active; docker pull meshtastic/meshtasticd up front so the pull is off the
simulator's node-boot path.
- e2e tests: cancel leftover loop tasks (watchdog) at loop teardown.
eric
ba31d79368