Stabilize operator dashboard active run updates

[yvette-carlisle]

Summary

• patch Running Lanes active run cards in place instead of replacing the full list on refresh
• preserve Debug Details disclosure state during refresh and active accordion animation
• smooth child activity bar width updates

Verification

• cargo test -p decodex operator_dashboard
• cargo +nightly fmt --all -- --check
• node dashboard script parse
• git diff --check
• mock dashboard browser DOM stability check