Add dual OTA partitions (ota_0/ota_1 × 1.75 MB each) and otadata to both esp32s3/balance/ and esp32s3/io/ on 4 MB flash layouts. Enable CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE and OTA HTTP on Balance. Create esp32s3/io/ project scaffold with config.h pin assignments. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>