feat: DirectorNotes and director_cues

[sebvanleuven]

Add DirectorNotes to PersonaConfig for session-wide director notes defaults at session-start, and Session.send_director_note_cue() to send turn-scoped director-note cues over the data channel. at_seconds/in_seconds are validated as finite client-side (non-finite values would serialize to invalid JSON). All other invalid cue semantics will log a warning and be ignored. Includes unit tests and README documentation.

---

Summary by cubic

Adds Director Notes to control avatar delivery style. Set session defaults with PersonaConfig(director_notes=...) and send turn-scoped cues with Session.send_director_note_cue(...); timing args must be finite and sends wait for the data channel.

• New Features

  • DirectorNotes dataclass and PersonaConfig(director_notes=...) for session-start defaults (e.g., preset_style, expressivity, custom_style_prompt); expressivity validated as finite.
  • Session.send_director_note_cue(tag, at_seconds?, in_seconds?) to send runtime cues over the data channel; rejects non-finite timing values and raises on send failure.
  • DirectorNotes exported from anam; README adds usage examples and validation notes.

• Refactors

  • Centralized data-channel readiness in _ensure_data_channel_open() and used it in send_message and interrupt for reliable sends.

^{Written for commit 8940f48. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 6 files

<sub>Reply with feedback, questions, or to request a fix.

Fix all with cubic | Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 2 files (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Fix all with cubic | Re-trigger cubic</sub>