Add a configurable voice cancel: saying "abbrechen" (or "cancel") at the start
or end of a clip discards the whole dictation — it is never routed onward,
rewritten, or typed. The rescue for accidentally triggered (e.g. wakeword)
recordings. Matched the same edge-anchored, ASR-tolerant way as routing keywords
via routing.is_cancel(), so the word buried mid-sentence won't trip it; checked
in Daemon._process right after transcription, before routing/rewrite/delivery.
Configurable via [routing] cancel_keywords (default ["abbrechen", "cancel"];
empty disables) and Settings -> Mic/Cues -> "Cancel words". The overlay briefly
shows "Abgebrochen". Docs (both READMEs) and CHANGELOG updated; tests cover the
matcher, the config round-trip, and the discard/deliver pipeline branches.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
