9d278ded5a68803c9b0b5cf3d06b1317ae161ecc
Covers the remaining state-transition edges: re-prime after an underrun goes idle (must re-accumulate TARGET_DELAY_FRAMES, not resume on one packet), duplicate-insert overwrite (no buffer growth), is_idle across fresh/buffering/ underrun, and overflow-resync when next_seq is already Some (playout head snaps to the new front). Jitter tests 6 -> 10; test-only, no prod change. Implemented by Gemini per next-task.md; left uncommitted per the operating- agreement default, reviewed against the real diff and re-verified (build + clippy --all-targets + test all green) by the senior. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>