Add MatchText field to NormalizedInput — a lossy lexical matching view
derived from ingress text: TrimSpace → NFKC → lowercase → collapse
Unicode whitespace. Does NOT fold ё→е, strip punctuation, strip wake
words, rewrite numbers, or invoke morphology.
Both ingress sites (voice + text) construct MatchText at entry. No
existing consumer reads MatchText yet — it is dark data for future
opt-in migration.
Vikunja: #725
