S60 reduced Tasmota trial image

This overlay targets Tasmota 15.6.0 and produces a native ESP32-C3 application image small enough for the stock S60’s 0x1f0000 OTA slots. The build uses Tasmota’s normal partition CSV only as a linker/factory-packaging aid; only the native app image is used, and its size is separately checked against the stock slot. It retains the web UI, MQTT, relay/button handling, and CSE7766-compatible energy metering while removing unrelated ESP32 features.

The trial build selects the peer OTA slot (the one-shot bridge) at the very start of setup(). A power cycle after the trial therefore enters the bridge, which in turn selects the trial image as its fallback. Do not remove this early fallback for the first hardware run.

Build from a clean Tasmota 15.6.0 source tree:

cp tasmota-s60/platformio_override.ini /tmp/Tasmota-15.6.0/platformio_override.ini
cp tasmota-s60/user_config_override.h /tmp/Tasmota-15.6.0/tasmota/user_config_override.h
patch -d /tmp/Tasmota-15.6.0 -p1 < tasmota-s60/early-fallback.patch
PLATFORMIO_CORE_DIR=/tmp/s60-pio-home-real .platformio-core/bin/pio run \
  -d /tmp/Tasmota-15.6.0 -e tasmota32c3-s60-trial

The image delivered through the bridge must be the app-only .bin, never a .factory.bin. On first boot, join the normal Tasmota setup AP using password s60-tasmota, configure Wi-Fi, and verify relay, button, LED, and metering.