Web details follow the current Session lifecycle
Web 详情栏遵循当前会话生命周期
The details entry is Session-scoped, but its preferred grid width is root-scoped. Selecting a different Session replaced the details content without closing that root preference, so the new owner inherited stale viewing geometry. Hero and other unselected states render no Session-scoped details; they need a derived zero track without becoming false owners in the comparison.
English
Problem
The details entry is Session-scoped, but its preferred grid width is root-scoped. Selecting a different Session replaced the details content without closing that root preference, so the new owner inherited stale viewing geometry. Hero and other unselected states render no Session-scoped details; they need a derived zero track without becoming false owners in the comparison.
Decision
AppFrame reads the current Session id and its blank summary flag from the authoritative Session projection. It records the last non-blank selected id only when that Session can own details, so hero and other unselected states neither trigger closure nor replace the last Session owner; their rendered details track derives as zero without changing the stored preference. The first Session preserves the layout store's initial preference, whose archived visibility-default decision chose closed; returning to the same Session restores its current width, and selecting a different Session closes the root-scoped details preference through the layout store before paint. The per-Session chat selection remains owned by the session-scoped store described by the slot system standard.
The layout store is transient and starts details closed. It neither reads nor writes localStorage, so reload restores the sidebar default and details closed and needs no Session-baseline exception. Manual close and reopen inside one unchanged Session retain their existing behavior. The lifecycle effect changes neither the Workspace-owned New Session flow, composer drafts, Session navigation, nor concession-chain resizing.
Alternatives considered
Close details in the New Session click handler. Rejected because an unselected surface has no Session-scoped details and must not mutate geometry. Closure belongs to the later comparison between two defined Session owners.
Persist panel geometry per Session. Rejected because the product contract needs stale context removed, not a new map of remembered widths. Per-Session geometry would also reopen details when users return, contrary to the chosen close-on-leave behavior.
Preserve persisted layout after the Session baseline is ready. Rejected because it duplicates startup lifecycle in a presentation component solely to validate stale viewing state. Transient defaults make reload deterministic without a readiness flag.
Treat every current-projection change as a Session switch. Rejected because startup materialization, hero, clearing selection, and invalidation are not transitions between two Session owners.
Consequences
Details starts closed, including when the first Session materializes. An explicit open action uses the contract default width. Switching to a different Session forgets a dragged details width because close writes zero and reopen uses that default. Unselected states derive a zero rendered track while leaving the preferred geometry unchanged; returning to the same Session through one of those states restores its width. Reload forgets sidebar geometry and restores details closed. The layout behavior test covers initial defaults, first materialization, direct and hero-mediated Session switches, same-Session return, and the absence of layout storage; the keyless browser e2e drives the same owner transitions through the shipped composition while checking the full grid track and browser errors.
中文
问题
详情入口由会话作用域拥有，而其首选网格宽度由根作用域拥有。选择不同会话时，系统会替换详情内容，却不会关闭根作用域的该首选宽度，因此新 owner 会继承陈旧的查看几何信息。hero 和其他未选中状态不会渲染会话作用域的详情；其轨道需派生为零宽度，但不能因此在比较中成为伪 owner。
决策
AppFrame 从权威会话投影读取当前会话 id 及其摘要中的 blank 标志。它只在该会话能够拥有详情时记录最后一个选中的非 blank 会话 id，因此 hero 和其他未选中状态既不会触发关闭，也不会替换最后一个会话 owner；这些状态下，详情栏轨道的渲染宽度派生为零，但存储的首选宽度不变。首个会话保留布局 store 的初始首选值，其已归档的可见性默认值决策选择关闭；返回同一会话时恢复其当前宽度；选择不同会话时，系统会先通过布局 store 关闭根作用域存储的详情栏首选宽度，再进行绘制。逐会话的聊天选中项继续由 slot 体系标准所述的会话作用域 store 拥有。
布局 store 是瞬时状态，详情栏在启动时保持关闭。它既不读取也不写入 localStorage，因此重新加载会恢复侧边栏默认值，并使详情栏保持关闭，无需会话基线例外。在同一个未变化的会话内手动关闭和重新打开详情栏，仍保持原有行为。该生命周期 effect 不改变 Workspace 拥有的 New Session 动线、composer 草稿、会话导航或让步链缩放。
考虑过的替代方案
在 New Session 点击处理器中关闭详情栏。 之所以否决：未选中表面没有会话作用域的详情，不得修改几何信息。详情栏是否关闭，应由随后对两个已定义会话 owner 的比较决定。
按会话持久化面板几何信息。 之所以否决：产品约定需要移除陈旧上下文，而不是新增一张保存各宽度的映射。按会话保存几何信息还会在用户返回时重新打开详情栏，与选定的离开即关闭行为相悖。
在会话基线就绪后保留持久化布局。 之所以否决：这会仅为验证陈旧的查看状态，在呈现组件中重复实现启动生命周期。瞬时默认值无需就绪标志即可使重新加载具有确定性。
将当前投影的每次变化都视为会话切换。 之所以否决：启动时的物化、hero、清除选中项和选中状态失效都不是两个会话 owner 之间的过渡。
后果
详情栏在启动时保持关闭，首次会话物化时亦然。显式打开操作会使用约定默认宽度。切换到不同会话会忘记拖动后的详情宽度，因为关闭操作会写入零值，重新打开时则使用该默认值。未选中状态会将轨道的渲染宽度派生为零，同时保持首选几何信息不变；经由这些状态返回同一会话时，会恢复其宽度。重新加载会忘记侧边栏几何信息，并使详情栏恢复关闭状态。布局行为测试覆盖初始默认值、首次物化、直接及经 hero 中转的会话切换、返回同一会话，以及不存在布局存储的情况；无密钥浏览器 e2e 则通过已交付的组合驱动相同的 owner 过渡，同时检查完整网格轨道和浏览器错误。