Spacebar push‑to‑talk interaction is unclear and undiscoverable

On the interview player / live interview screen, the spacebar push‑to‑talk interaction is not obvious or discoverable. Users may not realize they need to hold the spacebar to speak or that this control exists at all. I expected a clear, visible prompt and state change for push‑to‑talk.

Steps to Reproduce

1. Open an interview session as a new user (no prior instructions).

2. Wait for the agent to ask a question and then try to respond.

3. Without being told, try to figure out how to speak to the agent.

4. Observe how long it takes to discover the spacebar interaction and how visible the affordance is.

Actual vs Expected Behavior

Actual: The push‑to‑talk behavior via spacebar is either not communicated or only subtly indicated, making it easy to miss.
Expected: The interface should explicitly instruct users (e.g., “Hold space to speak”) and show a strong visual state change when the spacebar is held (e.g., mic icon lights up, “Listening…” label).