Fix ultrawide workspace utilization

CHANGELOG.md

@@ -15,6 +15,7 @@
 - At tile `512`, overlap `64`, threshold `0.15` and QA match IoU `0.25`, seven persisted AOIs reached mean precision `0.5898`, recall `0.5770`, F1 `0.5825` and minimum F1 `0.5528`; all three pure-empty controls remained at zero detections.
 - Fixed-reference evidence reduced false negatives from 7,753 to 6,182, including 745 fewer 25-100 m2 misses and 181 fewer sub-25 m2 misses. Precision is lower, so the UI states the increased false-positive review load explicitly.
 - Added persistent false-negative area summaries/GeoJSON, explicit tile-corpus sample selection provenance, missing runtime evaluation scripts, Docker COPY-source regression checks and warning-free Pydantic model-field schemas.
+- Fixed ultrawide two-panel workspaces so AI Labs, QA/QC and Exports use the available main width instead of leaving empty third/fourth columns, and decoupled backend README edits from the expensive all-in-one GIS/AI dependency cache layer.
 - Guarded activation updated only the Tower AI/model environment values; no fake outputs, provider fetching, API contract or database migration changed.
 
 ## Sprint 173 Expanded building model promotion (2026-07-13)