Text Intervention: track request, mood change, free instruction

[zeevenn]

Parent

#39 — PRD: AI Radio — Host-driven Channel experience with chat timeline

What to build

Wire the text input bar on the Radio Screen to the Intervention flow. When the user submits text, it is classified, appended to the chat timeline, and handed to the Programme Manager to regenerate the Programme.

Intervention classification: the Host Service already accepts an Intervention with a kind field. Classification can be done client-side with a lightweight heuristic, or by asking Claude as part of generateProgramme. For v1, pass the raw text as kind: 'free-instruction' — the Host interprets it. Track Requests and Mood Changes are handled by the Host's prompt logic without needing a separate client-side classifier.

Flow:

1. User types and submits text in the input bar
2. { type: 'user-turn', text, timestamp } appended to Chat Timeline immediately — input clears
3. A loading indicator appears in the chat (e.g. "Host is preparing the next set...")
4. programmeManager.handleIntervention({ kind: 'free-instruction', text }) is called
5. When the Host responds, { type: 'host-turn', text: acknowledgement, timestamp } is appended (the acknowledgement text comes from the Host's Claude response)
6. Current Track finishes, new Programme begins

The mic button remains a stub in this slice (wired in #50).

Acceptance criteria

• Submitting text appends a user-turn message to the timeline immediately
• A loading/pending state is visible in the chat while the Host generates the new Programme
• A host-turn acknowledgement message appears after the Host responds
• The new Programme (with the Intervention honoured) begins after the current Track finishes
• The text input clears after submission and is re-enabled after the Host responds
• Requesting a specific track by name results in that Track appearing in the new Programme

Blocked by

• Radio Screen shell + Chat Timeline Store #44 (Radio Screen shell — text input bar)
• Programme Manager: Channel tap → live AI radio #46 (Programme Manager — handleIntervention)