fix: fit the story graph to the window and scroll each column on its own

docs/features/conversation-supervision/ui-design.md

@@ -103,6 +103,8 @@ Modal 按[共享表单 Modal 规则](../../../UI-DESIGN.md#615-表单-modal)复
 
 使用 `supervisor` 页面壳层，最大内容宽度为 `1440px`。当前生产图谱左侧为紧凑的事件、实体和关系列表，中间为 SVG 画布，右侧为详情与来源。桌面列宽为 `216px minmax(0, 1fr) 280px`，画布获得主要空间。外圈事件按发生时间排序后等距逆时针排列，不表示实际时间间隔；起止之间保留缺口和方向箭头。内部显示真实实体名称，实线仅连接实际事件与实体，虚线仅连接实际实体关系。
 
+高度：容器宽度不小于 861px 时，图谱这一行的高度等于窗口可见高度减去图谱顶部位置，并在底部保留约 24px 边距（不小于页面底部内边距），最低 420px。三栏时整页不再出现纵向滚动；左侧列表、中间画布、右侧详情各自在这一行内独立滚动，滚动只影响自身，不带动页面。两栏（861～1190px）时第一行按同样方式填满，详情换到下一行，保持自然高度并随页面滚动。单栏保持原有页面滚动和列表 320px 上限。窗口大小或图谱上方内容（提示、工具栏）变化时重新计算。
+
 实体及其影响连线复用现有 `--graph-node-*-border` 令牌；颜色用于辅助辨认实体，不代表故事分类或确认状态。选中项加粗并突出连线，其余节点降低图形强调度但保留可读文字。详情分为名称与说明、图谱关联、确认操作和来源，来源正文按需读取。图例常显，读图说明可展开。
 
 画布每批最多显示 8 个事件、6 个实体；同时间事件分开排布。列表保留全部返回记录和完整名称，选择实体会定位到真实关联事件所在批次，选择关系会优先显示两端实体。滑块明确命名“事件浏览”，只切换当前事件，不还原实体历史状态，也不宣称完整历史回放。当前接口返回单条故事线，不复制 Demo 中的三条模拟故事。后续视图规划见[图谱设计](../story-graph/prd.md)。

src/renderer/src/SupervisorWorkspace.tsx

@@ -6,6 +6,7 @@ import type { SupervisionReviewExecution } from '../../shared/supervision-review
 import { EmptyState, PageTabs } from './WorkspacePrimitives'
 import { SupervisionDiscussion } from './SupervisionDiscussion'
 import { SupervisionStoryDigest } from './SupervisionStoryDigest'
+import { useFillHeight } from './use-fill-height'
 import { SupervisionEventStory, SupervisionExperienceDetail, SupervisionExperienceList, SupervisionStoryDetail, SupervisionStoryList, useSupervisionStories } from './SupervisionStories'
 import type { AssistantProject } from '../../shared/assistant-contracts'
 import { heartbeatScopeSchema } from '../../shared/assistant-contracts'
@@ -478,6 +479,8 @@ export function SupervisorWorkspace({
     ? (JSON.parse(graph.storyLine.scope_json) as SupervisionRunRequest['scope'])
     : undefined
   const storyState = useSupervisionStories(graphScope, tab === 'graph', graph)
+  const graphLayoutRef = useRef<HTMLDivElement>(null)
+  useFillHeight(graphLayoutRef, tab === 'graph' && graph.events.length > 0)
   // The work review reads the selected result's own scope, so it matches the period shown.
   const recapStories = useSupervisionStories(latest?.scope, tab === 'overview', latest?.id)
   const selectedStory = selection?.kind === 'story' ? storyState.view.stories.find((story) => story.id === selection.id) : undefined
@@ -718,7 +721,7 @@ export function SupervisorWorkspace({
                 />
               )}
               {graph.events.length > 0 && (
-                <div className="supervisor-workspace__graph-layout">
+                <div className="supervisor-workspace__graph-layout" ref={graphLayoutRef}>
                   <aside
                     className="supervisor-workspace__graph-list"
                     aria-label={t('supervisor.selection')}

src/renderer/src/supervisor-workspace.css

@@ -388,6 +388,41 @@
 .supervisor-workspace__graph-canvas {
   border-inline: 1px solid var(--border-default);
 }
+/*
+ * Wide layouts: the graph row is as tall as the window allows (`--fill-height`, set by useFillHeight with a
+ * steady bottom margin), and each column in it scrolls on its own, so long lists never grow the page.
+ * With three columns that is the whole layout; with two, the detail wraps below at its natural height.
+ * Single-column layouts keep page scrolling.
+ */
+@container supervisor (min-width: 861px) {
+  .supervisor-workspace__graph-layout {
+    grid-template-rows: var(--fill-height, auto);
+    grid-auto-rows: auto;
+  }
+  .supervisor-workspace__graph-canvas,
+  .supervisor-workspace__graph-layout > .supervisor-workspace__detail {
+    min-height: 0;
+    max-height: var(--fill-height, none);
+    overflow-y: auto;
+    overscroll-behavior: contain;
+    scrollbar-width: thin;
+    scrollbar-gutter: stable;
+  }
+  .supervisor-workspace__graph-list {
+    contain: none;
+    height: 100%;
+  }
+  .supervisor-workspace__graph-list > .supervisor-workspace__list-panel {
+    overscroll-behavior: contain;
+    scrollbar-gutter: stable;
+  }
+}
+@container supervisor (min-width: 861px) and (max-width: 1190px) {
+  .supervisor-workspace__graph-layout > .supervisor-workspace__detail {
+    max-height: none;
+    overflow-y: visible;
+  }
+}
 .supervisor-workspace__canvas-heading {
   display: flex;
   justify-content: space-between;

src/renderer/src/use-fill-height.ts

@@ -0,0 +1,36 @@
+import { useLayoutEffect, type RefObject } from 'react'
+
+/**
+ * Sets `--fill-height` on the element: the visible height of its scroll container from the element's
+ * top down, minus `bottomGap`, never below `minimum`. Lets a panel fill the window with a steady bottom
+ * margin while its columns scroll inside, instead of growing the page with their content.
+ * Measured with the container scrolled to the top, so scrolling does not change the value.
+ */
+export function useFillHeight(ref: RefObject<HTMLElement | null>, enabled: boolean, bottomGap = 24, minimum = 420): void {
+  useLayoutEffect(() => {
+    const element = ref.current
+    if (!element || !enabled) return
+    let container: HTMLElement | null = element.parentElement
+    while (container && !/(auto|scroll)/.test(getComputedStyle(container).overflowY)) container = container.parentElement
+    const scroller = container ?? document.documentElement
+    const measure = () => {
+      const top = element.getBoundingClientRect().top - scroller.getBoundingClientRect().top + scroller.scrollTop
+      const padding = parseFloat(getComputedStyle(scroller).paddingBottom) || 0
+      // The layout's own border sits outside the row; subtract it so the outer box ends exactly at the gap.
+      const style = getComputedStyle(element)
+      const borders = (parseFloat(style.borderTopWidth) || 0) + (parseFloat(style.borderBottomWidth) || 0)
+      const height = Math.max(minimum, Math.floor(scroller.clientHeight - top - Math.max(bottomGap, padding) - borders))
+      element.style.setProperty('--fill-height', `${height}px`)
+    }
+    measure()
+    const observer = new ResizeObserver(measure)
+    observer.observe(scroller)
+    // Content above the element (notices, toolbars, headers) moves its top: observe earlier siblings up the tree.
+    // Parents are not observed, since the element's own height changes theirs.
+    for (let node: HTMLElement | null = element; node && node !== scroller; node = node.parentElement) {
+      for (let sibling = node.previousElementSibling; sibling; sibling = sibling.previousElementSibling) observer.observe(sibling)
+    }
+    window.addEventListener('resize', measure)
+    return () => { observer.disconnect(); window.removeEventListener('resize', measure); element.style.removeProperty('--fill-height') }
+  }, [ref, enabled, bottomGap, minimum])
+}

tests/support/supervisor-layout-driver.mjs

@@ -824,6 +824,38 @@ app
       await settle()
       await writeFile(join(artifacts, `dense-bottom-${width}.png`), (await win.webContents.capturePage()).toPNG())
     }
+    // The graph row fills the window down to a steady bottom margin; each column scrolls on its own.
+    for (const [width, height] of [[1440, 900], [1440, 700], [1024, 800]]) {
+      win.setContentSize(width, height)
+      await settle()
+      const fill = await js(`(() => {
+        const shell = document.querySelector('.page-shell');
+        shell.scrollTop = 0;
+        const layout = document.querySelector('.supervisor-workspace__graph-layout');
+        const shellBox = shell.getBoundingClientRect(), box = layout.getBoundingClientRect();
+        const columns = [...layout.children].map(column => {
+          const scroller = column.matches('.supervisor-workspace__graph-list') ? column.querySelector('[role=tabpanel]') : column;
+          const r = column.getBoundingClientRect();
+          return { name: column.className.split(' ')[0], top: r.top, bottom: r.bottom, scrolls: getComputedStyle(scroller).overflowY,
+            clientHeight: scroller.clientHeight, scrollHeight: scroller.scrollHeight };
+        });
+        // Bottom of the first grid row (the side-by-side columns), measured from the window bottom.
+        const rowBottom = Math.max(...columns.filter(column => Math.abs(column.top - columns[0].top) < 1).map(column => column.bottom));
+        return { bottomGap: shellBox.bottom - rowBottom, wrapped: columns.length - columns.filter(column => Math.abs(column.top - columns[0].top) < 1).length,
+          height: box.height, pageScroll: shell.scrollHeight - shell.clientHeight, columns };
+      })()`)
+      reports.push({ fill: { width, height, ...fill } })
+      await writeFile(join(artifacts, `fill-${width}x${height}.json`), JSON.stringify({ width, height, bottomGap: Math.round(fill.bottomGap), wrapped: fill.wrapped, pageScroll: fill.pageScroll, rowHeight: Math.round(fill.columns[0].bottom - fill.columns[0].top) }))
+      assert(fill.bottomGap >= 20 && fill.bottomGap <= 40, `Graph must stop above the window bottom: ${JSON.stringify(fill)}`)
+      // Three columns fit the window with no page scroll; at two columns only the wrapped detail extends the page.
+      if (!fill.wrapped) assert(fill.pageScroll <= 1, `Page must not scroll at three columns: ${JSON.stringify(fill)}`)
+      const sideBySide = fill.columns.filter(column => Math.abs(column.top - fill.columns[0].top) < 1)
+      for (const column of sideBySide) {
+        assert(Math.abs(column.bottom - sideBySide[0].bottom) < 1, `Columns must share the row height: ${JSON.stringify(fill)}`)
+        assert(['auto', 'scroll'].includes(column.scrolls), `Column must scroll on its own: ${JSON.stringify(column)}`)
+      }
+      await writeFile(join(artifacts, `fill-${width}x${height}.png`), (await win.webContents.capturePage()).toPNG())
+    }
     win.setContentSize(1440, 1100)
     await js(
        'document.querySelectorAll(".supervisor-workspace__graph-list [role=tab]")[2].click()'