Harden LoRa trunk reliability and multi-hop delivery

[callebtc]

Summary

• replace per-fragment stop-and-wait with an addressed v3 trunk protocol using selective-repeat bitmap feedback and terminal completion
• add atomic priority scheduling, transport reservation before Noise nonce consumption, bounded multi-hop forwarding, duplicate suppression, and per-neighbor link adaptation
• derive SX1262 deadlines from airtime, validate regional/PHY profiles, verify critical radio configuration, and recover from BUSY/IRQ failures with an independent watchdog
• add deterministic host coverage, loss/reordering simulations, hardware-smoke tooling, and protocol/testing documentation

Scope

This PR is based directly on upstream main. It contains no additional board-support or display changes; the existing XIAO ESP32-S3 with Wio-SX1262 wiring remains unchanged.

Testing

• ./tools/run_lora_host_tests.sh — all native module tests and 30 deterministic Python system tests pass
• ESP-IDF 6.0 release build for esp32s3
• ESP-IDF 6.0 release build for esp32c3 (BLE-only fallback)