reItalic (_text_) ran after reLink converted [text](url) to <a href>,
injecting <i> tags into URLs containing underscores (e.g. Google Flights
URL-safe base64 in the tfs param). Telegram silently dropped such malformed
<a> tags, causing only 1 of 3 links to appear in messages.
Fix: extract markdown links into placeholders before any formatting runs,
restore them as <a href> last — same pattern used for code blocks.
c36b06a901