Switch eight S3 board defaults and 78 remaining TinyUSB recipes to hardware Serial/JTAG while preserving UART and other platforms. Restore retained S3 PHY ownership after a TinyUSB OTA restart and prepare KISS queues before enabling the driver.
Add real recipe resolution, Companion/KISS transport sanitizer coverage, and RF lifecycle reset regressions to CI. Native tests pass 1765/1765; SDK, transport, recipe and USB watchdog checks pass. Board and role cross-compilation and physical OTA qualification continue.
Backport the pinned Arduino 2.0.17 HWCDC suffix and interrupt handling into a build-local source copy. Preserve unsent bytes, serialize ISR and producer rearm, and include FIFO, suffix and active writers in transport cleanup proofs without changing the loop stack allocation.
Validate zero and short writes, producer races, quarantine and stale cleanup with sanitizer-backed native tests and negative controls. Keep other frameworks and USB modes on their existing drivers; update the watchdog file mock for the existing buffer API.
mikecarper