Defense-in-depth + salvage for sessions captured before the adapter fix: drop any
vision-source span whose single unbroken duration covers ≥60% of the call. No one
speaks that long without a break, so it's a stuck/false active-speaker cue that
would dominate backend name attribution. Self (mic_vad) spans are never dropped.
Applied to both the live and re-process paths. Test added; 66 pass.
Grant Gilliam
1b6bb8ab67