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>
164f938982