Decomp-first per the block's rule: the research doc
(docs/research/2026-08-13-retail-ui-display-change.md, committed here)
pulled retail's actual mechanism before any code. A display change runs
UIElementManager::RefreshEvent @0x0045C530 ->
UIElement::UpdateForParentSizeChange @0x00462640, which unconditionally
re-applies every floating window's own clamping MoveTo override
(x = max(0, min(x, parentW - selfW)) - top-left priority, oversized
windows pin to 0), then broadcasts global message 0xE whose sole
listener reloads the per-resolution auto layout. No proportional moves,
no resets; retail saves layouts only via @saveui.
Port: RetailWindowLayoutPersistence.ClampAllToScreen() is the cascade
clamp (no store I/O; _restoring suppresses the per-move save so a live
drag-resize cannot write settings.json per frame), and
RetailUiRuntime.Draw carries a two-step screen-size edge detector:
change frame -> clamp; first stable frame -> one
RestoreAll(saveBack:false) per-resolution reload (the 0xE analog; no
lazy save-back, matching retail's save-only-on-command). The login
restore path already used retail's exact clamp math (Apply) - the live
trigger was the missing half, which is precisely the stranding the user
reported.
Deliberate deviation, register AD-91: retail's gmFloatyChatUI windows
have NO clamp and can strand; the block's requirement ("UI windows must
stay reachable") clamps every registered window uniformly.
Tests: 5 new persistence facts (clamp/top-left-pin/no-move/no-save-on-
clamp/no-save-on-live-reload). App suite 4,967/3 skips. Gate script
section D3 filled in.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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