feat(chat): 编辑摘要卡片弹窗改为锚定定位并修复深色近黑样式

- 弹窗水平相对编辑卡片居中，垂直优先锚定条目上方（空间不足自动翻到下方），高度吃满可用空间
- 行 hover 改用 --hover-bg（深色提亮），弹窗头部去近黑衬底改用分隔线
- 行高亮 is-active 仅钉住态挂载，修复 hover 消失延迟

static/src/components/chat/EditSummaryCard.vue

@@ -49,6 +49,11 @@ const totals = computed(() => {
 // ---------------- 弹窗状态 ----------------
 const activePath = ref<string | null>(null);
 const pinned = ref(false);
+const cardRef = ref<HTMLElement | null>(null);
+const anchorEl = ref<HTMLElement | null>(null);
+// 桌面端弹窗的内联定位样式（水平相对卡片居中、垂直锚定条目上方）；
+// 移动端保持空对象，回退到 CSS 的屏幕居中布局。
+const panelStyle = ref<Record<string, string>>({});
 let openTimer: ReturnType<typeof setTimeout> | null = null;
 let closeTimer: ReturnType<typeof setTimeout> | null = null;
 
@@ -57,6 +62,76 @@ const activeFile = computed<SummaryFile | null>(() => {
   return files.value.find((f) => f.path === activePath.value) || null;
 });
 
+// ---------------- 弹窗定位（桌面端） ----------------
+const PANEL_MAX_WIDTH = 720;
+const VIEWPORT_MARGIN = 16;
+const MIN_PANEL_HEIGHT = 140;
+// 条目上方至少要有这么多可用空间才放上面，否则优先考虑下方
+const PREFER_ABOVE_MIN_HEIGHT = 260;
+
+function computePanelStyle() {
+  if (isMobile.value || !cardRef.value || !anchorEl.value) {
+    // 移动端 / 无锚点：回退到 CSS 的屏幕居中布局
+    panelStyle.value = {};
+    return;
+  }
+  const vw = window.innerWidth;
+  const vh = window.innerHeight;
+  const width = Math.min(PANEL_MAX_WIDTH, vw - VIEWPORT_MARGIN * 2);
+
+  // 水平：相对编辑卡片左右居中（而不是相对屏幕），并夹取在视口内
+  const cardRect = cardRef.value.getBoundingClientRect();
+  const centerX = cardRect.left + cardRect.width / 2;
+  const left = Math.min(
+    Math.max(centerX - width / 2, VIEWPORT_MARGIN),
+    vw - width - VIEWPORT_MARGIN
+  );
+
+  // 垂直：优先放条目上方（底边 = 条目上边缘 - 半个条目高，向上生长）；
+  // 上方空间不足且下方更宽裕时改放下方（顶边 = 条目下边缘 + 半个条目高，向下生长）。
+  // 两个方向的高度都吃满该方向的可用空间，无固定上限。
+  const rowRect = anchorEl.value.getBoundingClientRect();
+  const anchorAbove = rowRect.top - rowRect.height / 2;
+  const anchorBelow = rowRect.bottom + rowRect.height / 2;
+  const spaceAbove = anchorAbove - VIEWPORT_MARGIN;
+  const spaceBelow = vh - VIEWPORT_MARGIN - anchorBelow;
+  const placeAbove = spaceAbove >= PREFER_ABOVE_MIN_HEIGHT || spaceAbove >= spaceBelow;
+
+  const base: Record<string, string> = {
+    left: `${Math.round(left)}px`,
+    width: `${Math.round(width)}px`,
+    transform: 'none'
+  };
+  if (placeAbove) {
+    const bottomEdge = Math.min(
+      Math.max(anchorAbove, VIEWPORT_MARGIN + MIN_PANEL_HEIGHT),
+      vh - VIEWPORT_MARGIN
+    );
+    panelStyle.value = {
+      ...base,
+      top: 'auto',
+      bottom: `${Math.round(vh - bottomEdge)}px`,
+      maxHeight: `${Math.round(bottomEdge - VIEWPORT_MARGIN)}px`
+    };
+  } else {
+    const topEdge = Math.min(
+      Math.max(anchorBelow, VIEWPORT_MARGIN),
+      vh - VIEWPORT_MARGIN - MIN_PANEL_HEIGHT
+    );
+    panelStyle.value = {
+      ...base,
+      top: `${Math.round(topEdge)}px`,
+      bottom: 'auto',
+      maxHeight: `${Math.round(vh - VIEWPORT_MARGIN - topEdge)}px`
+    };
+  }
+}
+
+function onWindowReposition() {
+  if (!activePath.value) return;
+  computePanelStyle();
+}
+
 function clearOpenTimer() {
   if (openTimer) {
     clearTimeout(openTimer);
@@ -71,16 +146,18 @@ function clearCloseTimer() {
   }
 }
 
-function open(path: string, pin: boolean) {
+function open(path: string, pin: boolean, rowEl: HTMLElement | null = null) {
   clearOpenTimer();
   clearCloseTimer();
   activePath.value = path;
   pinned.value = pin;
+  anchorEl.value = rowEl;
+  computePanelStyle();
 }
 
-function scheduleOpen(path: string) {
+function scheduleOpen(path: string, rowEl: HTMLElement | null) {
   clearOpenTimer();
-  openTimer = setTimeout(() => open(path, false), 150);
+  openTimer = setTimeout(() => open(path, false, rowEl), 150);
 }
 
 function scheduleClose() {
@@ -91,10 +168,10 @@ function scheduleClose() {
   }, 200);
 }
 
-function onRowMouseEnter(path: string) {
+function onRowMouseEnter(path: string, e: MouseEvent) {
   if (isMobile.value) return;
   clearCloseTimer();
-  scheduleOpen(path);
+  scheduleOpen(path, (e.currentTarget as HTMLElement) || null);
 }
 
 function onRowMouseLeave() {
@@ -111,9 +188,9 @@ function onPanelMouseLeave() {
   if (!isMobile.value) scheduleClose();
 }
 
-function onRowClick(path: string) {
+function onRowClick(path: string, e: MouseEvent) {
   // 点击 = 钉住（桌面与移动端一致；移动端无 hover，这是唯一入口）
-  open(path, true);
+  open(path, true, (e.currentTarget as HTMLElement) || null);
 }
 
 function close() {
@@ -121,6 +198,7 @@ function close() {
   clearCloseTimer();
   pinned.value = false;
   activePath.value = null;
+  anchorEl.value = null;
 }
 
 function onKeydown(e: KeyboardEvent) {
@@ -132,8 +210,13 @@ function onKeydown(e: KeyboardEvent) {
 watch(activePath, (v) => {
   if (v) {
     window.addEventListener('keydown', onKeydown);
+    window.addEventListener('resize', onWindowReposition);
+    // 捕获阶段监听滚动，让弹窗在对话区滚动时始终贴着锚定条目
+    window.addEventListener('scroll', onWindowReposition, true);
   } else {
     window.removeEventListener('keydown', onKeydown);
+    window.removeEventListener('resize', onWindowReposition);
+    window.removeEventListener('scroll', onWindowReposition, true);
   }
 });
 
@@ -141,6 +224,8 @@ onBeforeUnmount(() => {
   clearOpenTimer();
   clearCloseTimer();
   window.removeEventListener('keydown', onKeydown);
+  window.removeEventListener('resize', onWindowReposition);
+  window.removeEventListener('scroll', onWindowReposition, true);
 });
 
 // ---------------- diff 行渲染辅助 ----------------
@@ -163,7 +248,7 @@ function lineNumber(line: any): string {
 </script>
 
 <template>
-  <div v-if="files.length" class="edit-summary-card">
+  <div v-if="files.length" class="edit-summary-card" ref="cardRef">
     <div class="edit-summary-card__header">
       <span
         class="icon icon-sm edit-summary-card__icon"
@@ -181,10 +266,10 @@ function lineNumber(line: any): string {
         v-for="file in files"
         :key="file.path"
         class="edit-summary-card__row"
-        :class="{ 'is-active': activePath === file.path }"
+        :class="{ 'is-active': pinned && activePath === file.path }"
-        @mouseenter="onRowMouseEnter(file.path)"
+        @mouseenter="onRowMouseEnter(file.path, $event)"
         @mouseleave="onRowMouseLeave"
-        @click.stop="onRowClick(file.path)"
+        @click.stop="onRowClick(file.path, $event)"
       >
         <span class="edit-summary-card__path" :title="file.path">{{ file.path }}</span>
         <span class="edit-summary-card__delta">
@@ -205,6 +290,7 @@ function lineNumber(line: any): string {
         ></div>
         <div
           class="es-modal__panel"
+          :style="panelStyle"
           role="dialog"
           :aria-label="`文件变更：${activeFile.path}`"
           @mouseenter="onPanelMouseEnter"
@@ -313,9 +399,12 @@ function lineNumber(line: any): string {
   font-size: 12.5px;
 }
 
+/* is-active 仅「点击钉住」时挂载，用于标识正在查看的文件；hover 预览不挂，
+   否则鼠标离开后会被 200ms 关闭计时器拖住，看起来像 hover 消失有延迟 */
 .edit-summary-card__row:hover,
 .edit-summary-card__row.is-active {
-  background: var(--surface-soft);
+  /* 用全局 hover token：深色下是白色微量 tint（提亮），避免 surface-soft 的近黑衬底 */
+  background: var(--hover-bg);
 }
 
 .edit-summary-card__path {
@@ -374,8 +463,8 @@ function lineNumber(line: any): string {
   height: 44px;
   padding: 0 12px;
   flex: none;
+  /* 与版本管理弹窗一致：头部不加衬底，靠分隔线区分（深色下避免近黑色块） */
   border-bottom: 1px solid var(--border-default);
-  background: var(--surface-soft);
 }
 
 .es-modal__header-icon {