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.

patches/bluepad32-sdl3-imu.patch

@@ -125,6 +125,24 @@ diff --git a/src/components/bluepad32/bt/uni_bt_bredr.c b/src/components/bluepad
          uni_hid_device_disconnect(device);
          uni_hid_device_delete(device);
          /* 'device' is destroyed, don't use */
+@@ -562,6 +567,17 @@ void uni_bt_bredr_on_gap_inquiry_result(uint16_t channel, const uint8_t* packet, uin
+         logi(", name '%s'", name_buffer);
+     }
+     logi("\n");
+ 
++    // Reconnect discovery is not a pairing request. Avoid paging nearby
++    // unpaired devices outside the explicit bondable window: their connection
++    // attempts compete with live controller input and native PCM for airtime.
++    if (!gap_get_bondable_mode()) {
++        link_key_t key;
++        link_key_type_t type;
++        if (!gap_get_link_key_for_bd_addr(addr, key, &type)) {
++            return;
++        }
++    }
++
+     supported = uni_hid_device_on_device_discovered(addr, name_buffer, cod, rssi) == UNI_ERROR_SUCCESS;
+     if (supported) {
 diff --git a/src/components/bluepad32/bt/uni_bt_le.c b/src/components/bluepad32/bt/uni_bt_le.c
 --- a/src/components/bluepad32/bt/uni_bt_le.c
 +++ b/src/components/bluepad32/bt/uni_bt_le.c