P1.5 follow-up: clarify director instruction text semantics

[Astroite]

Follow-up

Director instruction text in P1.3 currently only infers the target persona. It is not persisted and is not passed as an ephemeral runtime instruction.

For P1.5 Director Controls, choose one of these paths:

1. Make this behavior explicit in UI copy.
2. Add a safe ephemeral director instruction path that affects only the next turn and does not become story fact.

Boundary

This should not block P1.3. It belongs to P1.5 Director Controls, not P1.4 Stage Presence UI.