494c719a5d
Migrate 54 test call sites to construct NormalizedInput{Text: ...}.
Add invariant tests:
- TestNormalizedInputReachesRouteIntact: ingress NormalizedInput reaches Route
- TestTryFastPathReceivesMatchText: TryFastPath gets the same input
- TestMatchTextDoesNotChangeRouting: same Text + different MatchText → same Decision
- TestDecisionUtteranceEqualsInputText: Decision.Utterance == input.Text