Implement Balmain snap-trigger flow and production pilot action pipeline (UI + API)

[Copilot]

This PR aligns the try-on pilot behavior with the requested architecture: Balmain brand interaction now triggers automatic snap/look transition, and the 5 native pilot actions are wired to real, stateful API flows. It also hardens interaction/state handling so UI transitions and backend side effects stay consistent under async activity.

• Balmain-triggered snap transition (UI state machine)

  • Added explicit Balmain brand triggers (button/link/logo) in TryOn projection panel.
  • Brand trigger now performs immediate garment transition and invokes the snap action path without user confirmation hops.
  • Consolidated snap/action pending states to prevent overlapping transitions and broken render phases.

• Pilot action integration in TryOn UI

  • Wired the 5 required actions to backend endpoints from client/src/pages/TryOn.tsx:
    • Mi Selección Perfecta → add selected look to cart with computed fit profile.
    • Reservar en Probador → create synchronous reservation and render returned QR.
    • Ver Combinaciones → fetch 5 suggestions and present 4 alternatives.
    • Guardar mi Silueta → persist structured biometric snapshot to profile.
    • Compartir Look → export clean composed image and register share event.
  • Added local action/result state (reservation id/QR, stored silhouette ref, alternative combinations) for deterministic UX feedback.

• API refactor for real pilot workflows

  • Extended SQLite-backed persistence in api/index.py with pilot tables for:
    • cart items,
    • stock locks/reservations,
    • silhouette profiles,
    • look share events.
  • Refactored pilot endpoints to enforce required inputs and return structured, actionable payloads.
  • Reservation flow now enforces stock locking semantics and conflict handling.
  • Combination endpoint returns normalized look_principal + alternativas shape.

• Privacy guardrails for shared look output

  • Added dedicated /api/lafayette/look/compartir endpoint.
  • Enforced metadata privacy policy: reject payloads containing weight/height/dimension/size fields.
  • UI share flow exports only composed visual output and sends privacy-safe metadata.

• Pilot API coverage

  • Added tests/test_lafayette_pilot.py for cart persistence, reservation lock/conflict behavior, combinations cardinality (5/4), silhouette storage, and share-metadata privacy blocking.

// Balmain brand trigger => immediate look transition + snap
const handleBalmainSnapTrigger = () => {
  onBalmainTrigger();
  void handleSnap("balmain");
};

[LVT-ENG]

Yes

[LVT-ENG]

Yes