Slice 2: ML — Streaming Session API + NDJSON Routing

Owner: ML engineer Domain: ML Complexity: L

Introduces the resource-oriented streaming session API and the NDJSON event stream that Core consumes.

Implement POST /streaming/sessions — response body remains open as application/x-ndjson
Implement POST /streaming/sessions/{id}/audio — audio chunk delivery
Implement DELETE /streaming/sessions/{id} — clean session termination with AssemblyAI buffer drain
Add NDJSON event types: transcript_segment, feature_vector, speaker_match, talking_point, task
Implement speaker identification logic and task extraction (~60s cadence)
Extend post-meeting pipeline to honour skip_tasks flag
Regenerate API spec: ./dev gen all

Test cases:

Test	Location	Assertion
Session lifecycle works end-to-end	`test_ml`	Create → audio → events stream → delete completes without error
All 5 NDJSON event types emitted	`test_ml`	Each event type appears in the stream with correct envelope
`skip_tasks=true` preserves live tasks	`test_ml`	Post-meeting pipeline does not call task extraction
Session conflict returns 409	`test_ml`	Second `POST /streaming/sessions` for same meeting → 409

ML — Streaming API