The @chat-adapter/telegram adapter hardcodes parse_mode=Markdown (legacy)
but its converter emits CommonMark. Messages containing **bold** or list
bullets that round-trip to `*` produce "can't parse entities" errors and
get dropped after retries.
Add an opt-in transformOutboundText hook on the chat-sdk bridge and wire
a Telegram-specific sanitizer that downgrades **bold** to *bold*, rewrites
dash/plus list bullets to a Unicode bullet so the adapter's re-stringify
doesn't inject stray `*`, and strips unbalanced delimiters or brackets.
Only Telegram opts in; other channels are unaffected.
Workaround until upstream (vercel/chat) ships mode-aware conversion —
PR #367 adds a parseMode knob but not the converter fix.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
