Labels now define distinct sessions — different power-cap configs
(asus_210w, sapphire_210w, asus_uncapped) render as separate bands
instead of merging into one. The label badge displays alongside
quant/engine/config badges rather than replacing them.
Scenario drilldown filters by label to prevent cross-band mixing.
Data fix: runs 22-32 (asus_210w) and 43-46 (asus_uncapped) reassigned
from Sapphire (gpu_id=11) to ASUS (gpu_id=12) — they were run on the
ASUS card but imported with the Sapphire GPU identity.
