MultistaticConfig::default().guard_interval_us was 5_000 us (5 ms) with a
comment claiming "well within the 50 ms TDMA cycle". That is wrong: on an
N-slot TDM schedule node k transmits in slot k, so two nodes are separated by
the slot offset, not clock jitter. A real 2-node mesh (slots 0/1) measured an
18,194 us spread, so every real frame set exceeded the 5 ms guard and fuse()
silently fell back to per-node sum/dedup -- multistatic fusion never ran on
hardware.
- Raise default hard guard to 60 ms (full 50 ms TDMA cycle + 20% jitter
headroom, derived from the slot model and documented in the field doc).
- Raise soft guard to 20 ms (just above the observed 18.2 ms 2-slot spread).
- Add MultistaticConfig::for_tdm_schedule(total_slots, slot_duration_us).
- Keep the honest per-node fallback for genuinely-mismatched frames.
Tests (fail on the old 5 ms default):
- fuse_real_tdm_spread_18194us_fuses_with_default_guard
- configurable_guard_rejects_too_large_spread
- for_tdm_schedule_invariants
Co-Authored-By: claude-flow <ruv@ruv.net>
287885776b