fix: revert SDK 36 bump, fix NimBLE setMTU crash, add --no-stub for OPI flash

AGENTS.md

@@ -19,7 +19,8 @@ ESP32-S3-PICO-1-N8R8 (Atom S3R Voice), 2 relais, 2 touch sensors (JR223B), BLE,
 
 - PlatformIO, `platform = espressif32@6.7.0`, board `esp32-s3-devkitc-1`
 - CDC USB serial (`ARDUINO_USB_CDC_ON_BOOT=1`), QIO OPI flash
-- Upload laptop: `pio run -t upload`, port `/dev/ttyACM0`, 115200 baud
+- **Upload:** `pio run -t upload` (via `--no-stub`, OPI flash vereist dit). Poort: **NOOIT `/dev/ttyACM0`** (dat is het Atreus toetsenbord). ESP32 herkennen via `ls /dev/serial/by-id/ | grep -i espressif` en die poort gebruiken. PlatformIO: pas `upload_port` in `platformio.ini` aan naar de gevonden poort.
+- **Direct flashen (handmatig):** `~/.platformio/packages/tool-esptoolpy/esptool.py --no-stub --chip esp32s3 --port /dev/ttyACM1 --baud 115200 --before default_reset --after hard_reset write_flash --flash_mode keep --flash_size keep 0x0 .pio/build/m5stack-atoms3r/bootloader.bin 0x8000 .pio/build/m5stack-atoms3r/partitions.bin 0xE000 ~/.platformio/packages/framework-arduinoespressif32/tools/partitions/boot_app0.bin 0x10000 .pio/build/m5stack-atoms3r/firmware.bin`
 - NVS: namespace "hmac", key "key" (32 bytes HMAC)
 - BLE advertising "SylDa_Server", HMAC-verified relay commands