Firmware rejected send_channel_text(1, ...) with "Unsupported command" because channel 1 isn't configured on the device. Revert to channel 0 for the DM wrapper — the 0xD1 marker + dest_prefix header still disambiguates DMs from plain public-channel text. Also revert Mesh.vue publicChannel back to index 0 so user-typed broadcasts target the same (only) working channel. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>