feat(native-usb): add 32-frame HD gameplay rumble and USB flight diagnostics

Preserve native frequency/amplitude timelines for DualSense PCM output,
remove the unsupported 64-frame path, and retain compatibility rumble for
other controllers. Use the validated 300 MHz sampling phase and restrict
non-bondable Classic discovery autoconnect to previously paired peers.

Buffer native-hub UART stdout and release USB IRQs around port-reset
callbacks. Add observer liveness and pre-SETUP root-response observations
without changing recovery behavior. Cover transport and haptics boundaries.

Record the user-accepted 0.108 trial: controls remained responsive and
rumble felt fine. Instrumentation changes timing; the disconnect root
cause and long-term reliability remain unqualified.

Validation: 624 tests, 11 affected firmware/probe builds, and on-device
concurrent USB and HD-auto-start checks. Private captures, generated
images, and unrelated working-tree files are intentionally excluded.

tests/test_switch2_usb_probe_protocol_native.py

@@ -101,6 +101,7 @@ def test_switch2_usb_probe_protocol(
             f"-DSWITCH2_PROBE_NEUTRAL_INPUT={int(hub)}",
             *([f"-DSWITCH2_PROBE_{imu_mode}=1"] if imu_mode else []),
             f"-I{probe}",
+            f"-I{root / 'src' / 'firmware'}",
             f"-I{tmp_path}",
             f"-I{mbedtls / 'include'}",
             str(probe / "protocol.c"),