Address review feedback (tick handling, reset handler, config & docs)

Addresses PR review comments:

- Fix WB55 Nucleo-64 wording in boards_txt_additions.txt
- Add build.enable_usb override to prevent duplicate STM32 core USB stack
- Correct README path to boards_txt_additions.txt
- Fix CFG_TUSB_RHPORT0_MODE to include speed bits
- Update TINYUSB_NEED_POLLING_TASK comment to reflect actual scheduling mechanism
- Rework HAL_IncTick() override to avoid hard-coded +1 tick increment
- Replace naked Reset_Handler C implementation with safe assembly wrapper + C handler

No functional changes beyond the requested fixes and clarifications.

Author: code-fiasco

README.md

@@ -50,7 +50,7 @@ Note: For ESP32 port, version before v3.0 requires all descriptors must be speci
 The following are cores without built-in support
 
 - **[stm32duino/Arduino_Core_STM32](https://github.com/stm32duino/Arduino_Core_STM32)**
-  - Still WIP. Fully functional but with limited number of MCUs supported so far (F1xx, F4xx, some G4xx & WB55). Requires lines added to stm32duino boards.txt which can be found in /ports/stm32/boards_txt_additions.txt. 
+  - Still WIP. Fully functional but with limited number of MCUs supported so far (F1xx, F4xx, some G4xx & WB55). Requires lines added to stm32duino boards.txt which can be found in src/arduino/ports/stm32/boards_txt_additions.tx
 
 - **mbed_rp2040**
   - It is still possible to use TinyUSB but with some limits such as:

src/arduino/ports/stm32/Adafruit_TinyUSB_stm32.cpp

@@ -147,16 +147,12 @@ void serialEventRun(void)
     yield();
 }
 
-// HAL_IncTick() is called every 1 ms from the SysTick_Handler ISR.
-// The STM32 HAL defines it as __weak, so we override it here.
-// We call the HAL's own uwTick increment, then set the flag for yield().
-extern "C" void HAL_IncTick(void)
+// Hook into the HAL SysTick callback instead of overriding HAL_IncTick().
+// This preserves the HAL's own tick behaviour (including configurable
+// tick frequency) while still giving us a reliable 1 ms-ish pump for
+// tud_task().
+extern "C" void HAL_SYSTICK_Callback(void)
 {
-    // Keep the HAL tick counter running (normally done by the weak default).
-    extern __IO uint32_t uwTick;
-    uwTick += 1U;
-
-    // Signal yield() to run tud_task() at the next thread-context opportunity.
     _tusb_task_pending = true;
 }
 

src/arduino/ports/stm32/dfu_boot_stm32wb.c

@@ -38,13 +38,21 @@ static void dfu_boot_check(void)
     }
 }
 
+// Minimal naked wrapper that sets SP and branches to the C reset handler.
 __attribute__((naked, used))
 void Reset_Handler(void)
 {
     __asm volatile (
-        "ldr r0, =_estack \n"
-        "mov sp, r0       \n"
+        "ldr r0, =_estack     \n"
+        "mov sp, r0           \n"
+        "b   Reset_Handler_C  \n"
     );
+}
+
+// Standard C reset handler: performs DFU check, system init, and
+// data/BSS initialisation before entering main().
+static void Reset_Handler_C(void)
+{
     dfu_boot_check();
     SystemInit();
     {

src/arduino/ports/stm32/tusb_config_stm32.h

@@ -26,7 +26,7 @@
 #define TUSB_CONFIG_STM32_H_
 
 // USB Port
-#define CFG_TUSB_RHPORT0_MODE  OPT_MODE_DEVICE
+#define CFG_TUSB_RHPORT0_MODE  (OPT_MODE_DEVICE | OPT_MODE_FULL_SPEED)
 #define CFG_TUSB_RHPORT0_SPEED OPT_FULL_SPEED
 #define CFG_TUSB_RHPORT1_MODE  OPT_MODE_NONE
 
@@ -80,10 +80,10 @@
 
 // TINYUSB_NEED_POLLING_TASK is intentionally NOT defined here.
 //
-// The STM32 port implements yield() to call tud_task() automatically
-// whenever the Arduino core calls yield() (e.g. inside delay(), and at
-// the bottom of every loop() iteration on cores that wrap loop() with
-// a yield() call). This means TinyUSB is serviced without any explicit
+// The STM32 port implements the STM32 port implementation
+// relies on a HAL tick hook plus serialEventRun() to ensure 
+// tud_task() runs even when the core doesn’t call yield() from loop(). 
+// This means TinyUSB is serviced without any explicit
 // TinyUSBDevice.task() call in the sketch's loop().
 //
 // Sketches that still contain the legacy polling guard: