The regression recurred because a floating timeline height was still exported as shared layout space and its z-index exceeded artifacts and notices. Reserve zero layout height and define the timeline below artifact and notification overlays.
Keep ScaleInfo pinned to the map corner and move the centered timeline above collisions, preventing the previous conditional offset from lifting the scale. Remove collapsed Agent rail width reservation and add timeline state transitions.
Unify the Agent history extension with the header acrylic surface, preserve the full conversation body, and consolidate shared control and status styling.
Restore map flow and SCADA controller behavior, remove obsolete rendering paths, and extend regression coverage. Button press coverage now releases outside the target so state assertions cannot accidentally toggle the control.
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