Signal's BodyRange (via signal-cli's textStyle) interprets start/length as
UTF-16 code units, but the Phase-3 assembly used Python's len(), which counts
code points. A single non-BMP character (e.g. an emoji) earlier in a message
shifted every subsequent styled span left by one unit, dropping the last
letter of bold/italic words.
Track a running UTF-16 offset in the assembly loop and add regression tests
covering emojis, supplementary CJK, ZWJ sequences, and a multi-section
message that mirrors the reported failure.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Integrates signal-cli daemon via HTTP JSON-RPC as a nanobot channel.
Supports DMs and group chats with open/allowlist access policies,
markdown→Signal text style conversion, typing indicators, attachment
handling, group message context buffering, and automatic reconnect
with exponential backoff.
Includes unit tests for channel lifecycle, message routing, mention
detection, markdown conversion, and message splitting.
Originally based on https://github.com/HKUDS/nanobot/pull/601.
