fix(cat): align model transition at edges

修复猫形态和人形态切换时靠近屏幕边界的过渡遮罩偏移。\n\n- 过渡遮罩按猫/模型中心直接定位，允许遮罩部分出屏\n- 保持猫/模型实体原有边界夹取不变\n- 补充静态契约测试，防止重新把遮罩夹回视口

Author: yiyiyiyiGKY

static/app-ui.js

@@ -1853,12 +1853,10 @@
             NEKO_MODEL_CAT_TRANSITION_MIN_SIZE,
             Math.min(NEKO_MODEL_CAT_TRANSITION_MAX_SIZE, Math.round(basis * NEKO_MODEL_CAT_TRANSITION_SIZE_FACTOR))
         );
-        const maxLeft = Math.max(0, window.innerWidth - size);
-        const maxTop = Math.max(0, window.innerHeight - size);
 
         return {
-            left: Math.max(0, Math.min(Math.round(centerX - size / 2), maxLeft)),
-            top: Math.max(0, Math.min(Math.round(centerY - size / 2), maxTop)),
+            left: Math.round(centerX - size / 2),
+            top: Math.round(centerY - size / 2),
             width: size,
             height: size,
         };

tests/unit/test_avatar_return_button_idle_tiers_static.py

@@ -155,6 +155,14 @@ def test_model_cat_transition_contract_is_present():
     assert "NEKO_MODEL_CAT_TRANSITION_MAX_SIZE = 680" in source
     assert "NEKO_MODEL_CAT_TRANSITION_SIZE_FACTOR = 0.86" in source
     assert "Math.round(basis * NEKO_MODEL_CAT_TRANSITION_SIZE_FACTOR)" in source
+    transition_rect_block = source[
+        source.index("function normalizeNekoTransitionRect(anchorRect, container, coverRect)"):
+        source.index("function clearNekoModelCatTransitionOverlay()")
+    ]
+    assert "left: Math.round(centerX - size / 2)" in transition_rect_block
+    assert "top: Math.round(centerY - size / 2)" in transition_rect_block
+    assert "maxLeft" not in transition_rect_block
+    assert "maxTop" not in transition_rect_block
     assert "const transitionAnchorRect = savedGoodbyeRect || activeReturnButtonContainer.getBoundingClientRect()" in source
     assert "function mergeNekoTransitionAnchorRect(anchorRect, coverRect)" in source
     assert "const coverRect = options.coverRect || null" in source