When a Telegram user replies using the native quote feature to select
only part of a prior message, _build_message_event was injecting the
ENTIRE replied-to message into reply_to_text via
message.reply_to_message.text/caption. python-telegram-bot exposes
the user-selected substring as message.quote (TextQuote.text); we now
prefer that and fall back to the full replied-to text only when no
native quote is present.
The agent-visible "[Replying to: \"...\"]" prefix can otherwise expand
the user's narrow quote into the full prior message, causing the agent
to act on unrelated actionable-looking text the user did not select
(e.g. multi-item briefings where the user quotes one bullet but the
prefix injects every bullet). Falls back cleanly when message.quote
is absent (PTB <21 or replies that don't quote a substring).
Fixes#22619
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
