Switch BT1035 bring-up from Line-In to I2S slave (AT+AUXCFG=3, AT+I2SCFG=67) to match the ADAU1701 PCM routing, confirm 2 kΩ I2C pull-ups on R1/R16, and sync firmware docs, AGENTS rules, and the DATASHEET bundle. Co-authored-by: Cursor <cursoragent@cursor.com>