Hero stays visible while a blank session opens
空白会话打开期间保持 hero 可见
The conversation root has a `settling` phase for a session that is still opening while its composer reads `blank`: the hero-versus-docked outcome is unknowable until history arrives, so the composer seat is hidden (`visibility:hidden`) rather than flashing the centered hero and snapping to the docked bar. Startup auto-selection turned that guard into the defect it was meant to prevent. From the no-workspace hero, `Wo
English
Problem
The conversation root has a settling phase for a session that is still opening while its composer reads blank: the hero-versus-docked outcome is unknowable until history arrives, so the composer seat is hidden (visibility:hidden) rather than flashing the centered hero and snapping to the docked bar. Startup auto-selection turned that guard into the defect it was meant to prevent. From the no-workspace hero, WorkspacesService.startInitialSelection connects the most recent workspace and opens its blank session; openState flips to loading the moment open() lands, so the center column went blank for the whole history round-trip and then repainted, which reads as a full-page refresh on every launch.
Decision
ConversationRoot reads the session list summary's blank flag alongside the conversation snapshot and exempts summary-proven blank sessions from settling: settling additionally requires summaryBlank !== true, and hero accepts a blank composer whenever the summary proves the session blank, in every open state rather than only loading. A session the list already reports as blank can only land on the hero, so hiding buys nothing and costs the visible flash; the same proof holds before the open starts (cold) and after one fails (error), where the previous conditions fell through to the active phase and rendered a docked bare composer under chrome ConversationSession hides for blank sessions. Whenever the summary does not prove the session blank — a row reporting blank: false, or no row at all because the list has not caught up — summaryBlank is not true and the conservative settling hide is unchanged.
The summary flag and the snapshot's own blank are distinct sources: the snapshot describes the session being opened, the summary is the list row that already exists before the open resolves. Only the latter is available early enough to decide the phase.
Alternatives considered
Drop the settling phase entirely. Rejected because it still earns its keep for a session with no summary row: without a prior claim about emptiness, hero-versus-docked is genuinely unknowable and the flash it prevents is the worse one.
Delay the loading flip until history returns. Rejected because openState is authoritative about the open operation; deferring it to suppress a presentation artifact would misreport the data state to every other consumer.
Cross-fade or otherwise animate the settling hide. Rejected because the column has nothing to show during the round-trip either way — the fix is to not hide content whose outcome is already known, not to decorate the hiding.
Deferred
Object-layer reference churn found while diagnosing this — no-op projections minting fresh snapshots, the create path projecting twice, select() using notifyNow from async continuations — is real but independent of the visible flash.
Consequences
Startup auto-selection renders the hero immediately and keeps the composer seat and header visible through the history round-trip, so launching into a recent workspace no longer looks like a page reload. Sessions whose summary does not prove them blank keep the previous settling behavior, so the guard still covers the case it was written for. Skeleton tests pin all three summary shapes: a row reporting blank: false settles, an absent row settles, and a summary-proven blank session opening under loading renders hero chrome with a live textarea.
The assembled coverage is apps/web/tests/startup-auto-selection.e2e.ts (keyless web browser lane). Its first Workspace connection asserts that the Hero root, Workspace chip, scroll body, composer seat, and textarea remain the same DOM nodes when the blank Session appears. It then holds the session.history response open at the browser's network boundary and asserts the visible frame while the auto-selected open is in flight — hero phase, hero title, painted composer — plus a recorded phase timeline of exactly ['hero'] for the whole load. Holding the round-trip is what makes the second case a regression test rather than a race: against a loopback host the open settles too fast to sample, and with the exemption reverted the held window is precisely when the root reports settling.
中文
问题
会话根节点为"正在打开且 composer 处于 blank"的会话保留了一个 settling 阶段：在历史记录返回之前，hero 与 docked 的归属不可知，因此宁可隐藏 composer 座位（visibility:hidden），也不要先闪出居中的 hero 再跳到底部输入条。启动时的自动选择把这道防护变成了它本要防止的缺陷。从无工作区的 hero 进入时，WorkspacesService.startInitialSelection 会连接最近的工作区并打开其空白会话；open() 一落地 openState 立即翻为 loading，中间栏因此在整个历史往返期间保持空白，随后重绘一次——每次启动看起来都像整页刷新。
决策
ConversationRoot 在读取会话快照的同时读取会话列表摘要的 blank 标志，并让"摘要已证明为空白"的会话豁免 settling：settling 额外要求 summaryBlank !== true，而 hero 在摘要证明会话为空白时接受处于 blank 的 composer——覆盖全部 open state，而非仅 loading。列表已报告为空白的会话只可能落到 hero，因此隐藏毫无收益，只换来一次可见闪烁；同一份证明在打开开始之前（cold）与打开失败之后（error）同样成立，而此前的条件会在这两种状态下落到 active 阶段，在 ConversationSession 为空白会话隐藏的外壳之下渲染出一条停靠的裸 composer。只要摘要没有证明会话为空白——无论是报告 blank: false 的行，还是列表尚未跟上因而根本没有该行——summaryBlank 都不为 true，保守的 settling 隐藏行为保持不变。
摘要标志与快照自身的 blank 是两个不同来源：快照描述正在打开的这个会话，摘要则是在打开操作完成之前就已存在的列表行。只有后者足够早，可用于决定阶段。
备选方案
彻底移除 settling 阶段。 否决，因为对没有摘要行的会话它仍有价值：在缺少任何关于"是否为空"的先验断言时，hero 与 docked 的归属确实不可知，而它所防止的那种闪烁更糟糕。
推迟 loading 的翻转，直到历史返回。 否决，因为 openState 是打开操作的权威状态；为了压制一个呈现层瑕疵而推迟它，会向其他所有消费者误报数据状态。
为 settling 的隐藏加交叉淡入或其他动画。 否决，因为无论如何该栏在往返期间都没有内容可展示——正确的修复是不隐藏结局已知的内容，而不是把隐藏装饰得好看些。
推迟事项
诊断期间发现的对象层引用抖动——空操作投影铸造出新的快照、创建路径重复投影一次、select() 在异步续体中使用 notifyNow——确实存在，但与这次可见闪烁相互独立。
影响
启动自动选择会立即渲染 hero，并在整个历史往返期间保持 composer 座位与 header 可见，因此启动进入最近工作区不再像页面重载。摘要未证明为空白的会话保持原有的 settling 行为，这道防护仍覆盖它当初针对的场景。骨架测试固定了摘要的三种形态：报告 blank: false 的行进入 settling；根本没有该行同样进入 settling；摘要已证明为空白的会话在 loading 期间渲染 hero 外壳与可用的文本框。
组装级覆盖是 apps/web/tests/startup-auto-selection.e2e.ts（无密钥的 Web 浏览器泳道）。首次连接 Workspace 时，它断言 blank Session 出现前后 Hero root、Workspace chip、滚动主体、composer seat 与 textarea 都是同一 DOM 节点。随后它在浏览器网络边界上扣住 session.history 的响应，并在自动选择的打开仍在飞行途中断言可见画面——hero 阶段、hero 标题、已绘制的 composer——外加整次加载记录到的阶段时间线恰好为 ['hero']。扣住这次往返正是第二个用例成为回归测试而非竞态的原因：对着回环主机，打开会快到无从采样；而一旦回退这条豁免，被扣住的这段窗口恰恰就是根节点报告 settling 的时刻。