feat(sim): add Burning Man DCR/DTP scenario

[Komzpa]

Summary

This is the Burning Man-specific remainder from stale PR #33, rebased onto the newer radio-policy stack instead of carrying the old monolithic patch forward.

The old PR #33 mixed several unrelated ideas:

• modem preset / coding-rate cleanup: split into the firmware-style preset and DCR work;
• radio/link-budget plumbing: split into the current RF/link-model/clutter/terrain stack;
• dynamic coding rate and dynamic TX power experiments: split into the draft DCR/DTP PRs;
• reusable PR33 helpers: split into refactor(sim): reuse PR33 link-budget helpers #77 where they are still generally useful;
• Burning Man-specific simulation logic: kept here as a draft follow-up because it depends on the DCR/DTP experiments.

What this PR adds on top of #77:

• burningManSim.py, a Burning Man scenario runner with router/client placement, clutter, environmental attenuation, and DCR/DTP toggles;
• per-node TX power support so scenario nodes can model routers and handheld clients with different base power;
• tests for per-node TX power and a tiny Burning Man smoke-case guard.

I deliberately did not carry over PR #33's old lib/signal.py: it was unused in the original branch and now duplicates the newer shared lib/link_model.py path with older dict/mock-node APIs.

Stack / review note

Draft because this sits at the end of the experimental queue. The useful generic pieces should be reviewed before this:

1. DCR policy (feat(sim): add dynamic coding rate policy #71)
2. DTP policy (feat(sim): add dynamic tx power policy #72)
3. reusable PR33 helpers (refactor(sim): reuse PR33 link-budget helpers #77)
4. this Burning Man scenario

The diff against master will look large until the lower stack lands. The actual delta over codex/pr33-remaining-optimizations is intentionally small: burningManSim.py, per-node TX power plumbing, and tests.

Validation

• /home/kom/proj/lora/Meshtasticator/.venv/bin/python -m unittest discover -s tests -v -> 170 tests OK
• git diff --check
• /home/kom/proj/lora/Meshtasticator/.venv/bin/python burningManSim.py 10 --simtime-seconds 5 --period-seconds 1 --dcr --dtp --phy-loss-model --capture-collision-model
  • produced non-empty simulation output, including DCR CR counts and DTP power histogram