refactor(Semantics/Modality): dedup ModalFlavor, de-echo Orthologic namespace

[hawkrobe]

Two mathlib-convention fixes from the Modality-layer audit:

• Dedup ModalFlavor: Farsi/Determiners and two Studies consumers had a 2-case local fork of the canonical 4-case Semantics.Modality.ModalFlavor; now import and use the canonical type.
• De-echo Orthologic namespace: Semantics.Modality.Orthologic to root-level Orthologic (namespace = concept, not directory path), matching the HistoricalAlternatives precedent; updates consumers.