新增 desktop CSS 变量快照，把 window-local workarea left/right、workarea size、history offset/center 纳入 compactSurfaceAnchorSnapshot

syncCompactSurfaceAnchor() 早退前会比较这些字段，窗口 origin/workArea 变化时不会跳过 CSS 变量刷新

Author: MingTianSang

static/app-react-chat-window.js

@@ -1123,6 +1123,29 @@
         };
     }
 
+    function getCompactDesktopCssVarSnapshot(layoutOverride) {
+        if (!layoutOverride) return 'desktop:none';
+        var parts = [];
+        if (layoutOverride.workArea) {
+            var workAreaWindowX = layoutOverride.windowBounds ? Math.round(layoutOverride.windowBounds.x) : Math.round(layoutOverride.workArea.left);
+            parts.push(
+                'workarea',
+                Math.round(layoutOverride.workArea.left - workAreaWindowX),
+                Math.round(layoutOverride.workArea.right - workAreaWindowX),
+                Math.round(layoutOverride.workArea.width),
+                Math.round(layoutOverride.workArea.height)
+            );
+        } else {
+            parts.push('workarea:none');
+        }
+        parts.push(
+            'history',
+            Math.round(layoutOverride.historyOffsetX || 0),
+            Number.isFinite(layoutOverride.historyCenterX) ? Math.round(layoutOverride.historyCenterX) : 'none'
+        );
+        return parts.join(':');
+    }
+
     function normalizeCompactDomRect(rect) {
         if (!rect) return null;
         var left = Number(rect.left);
@@ -1633,7 +1656,8 @@
             Math.round(target.top),
             Math.round(target.width),
             Math.round(target.height || COMPACT_SURFACE_DEFAULT_HEIGHT),
-            (!!(dragState && dragState.compactSurface) || compactSurfaceDesktopDragActive) ? 'dragging' : 'idle'
+            (!!(dragState && dragState.compactSurface) || compactSurfaceDesktopDragActive) ? 'dragging' : 'idle',
+            getCompactDesktopCssVarSnapshot(layoutOverride)
         ].join(':');
         if (snapshot === compactSurfaceAnchorSnapshot) {
             return;

tests/unit/test_react_chat_window_static.py

@@ -205,6 +205,19 @@ def test_desktop_compact_history_uses_workarea_not_browserwindow_viewport():
     assert "var workAreaWindowX = layoutOverride.windowBounds ? Math.round(layoutOverride.windowBounds.x) : Math.round(layoutOverride.workArea.left);" in script
     assert "Math.round(layoutOverride.workArea.left - workAreaWindowX) + 'px'" in script
     assert "Math.round(layoutOverride.workArea.right - workAreaWindowX) + 'px'" in script
+    assert "function getCompactDesktopCssVarSnapshot(layoutOverride)" in script
+    assert "Math.round(layoutOverride.workArea.left - workAreaWindowX)" in script
+    assert "Math.round(layoutOverride.workArea.right - workAreaWindowX)" in script
+    assert "Number.isFinite(layoutOverride.historyCenterX) ? Math.round(layoutOverride.historyCenterX) : 'none'" in script
+
+    sync_anchor_block = script.split("function syncCompactSurfaceAnchor()", 1)[1].split(
+        "function stopCompactMinimizeBallTracking()",
+        1,
+    )[0]
+    assert "getCompactDesktopCssVarSnapshot(layoutOverride)" in sync_anchor_block
+    assert sync_anchor_block.index("getCompactDesktopCssVarSnapshot(layoutOverride)") < sync_anchor_block.index(
+        "if (snapshot === compactSurfaceAnchorSnapshot)"
+    )
 
     desktop_history_block = styles.split(
         "body.electron-chat-window.subtitle-web-host .compact-export-history-anchor",