notify-send passes the body to the notification server as markup, and
Plasma renders links, emphasis and images in it. Bodies carry CLI text
such as provider status messages and extra quota labels, so a status
message containing an anchor became a clickable link to any address,
bypassing the host-pinned status URL rule, and a literal "<" or "&"
could vanish.

NotificationCommand now escapes &, < and > in the bounded body. The
summary is plain text by specification and stays literal.

Tests: tst_notification_command covers links, images, entities, the
action and fallback sends, and the bound applied before escaping; both
cases fail on main. The real notify-send dispatcher test now expects the
escaped body.

Documentation: development and usage guides, CHANGELOG Unreleased.


Claude-Session: https://claude.ai/code/session_0118rYiu37HnKdYedpUff1cT

Co-authored-by: Claude <noreply@anthropic.com>