fix(web): 四个页面共用一份会话列表，空会话不入列

对话、星盘、星历、报告进同一 (app) 外壳，列表只拉一次。服务端不再列出空咨询；新建复用已有空会话。新标题改成「生时校正 · M月D日」，侧栏副标题用创建时间。

frontend/DESIGN.md

@@ -327,7 +327,7 @@ The birth-time rectification session is the consultation transcript plus a house
 
 ### Navigation item
 
-- **Structure:** title, optional subtitle for another person's chart, current-state marker.
+- **Structure:** title is the session name. New dated titles are `生时校正 · M月D日` / `今日节奏 · M月D日` (category first). Subtitle is always `M月D日 HH:MM` in Asia/Shanghai from `created_at`, plus ` · <chart name>` when the chart is not the account holder. Same-day duplicates are not uniquified with wall-clock `HH:MM`.
 - **States:** default, hover, current, focus, disabled.
 - **Hierarchy:** section labels stay tertiary; session titles and primary actions use ink so history rows do not collapse into the same gray as “收藏对话 / 历史对话”. History groups use the overline token for “今天 / 昨天 / 最近 7 天 / 最近 30 天 / 更早”. When the chart is not the account holder, a secondary line shows the chart name under the title. A session title is named when it is created; opening a stored session must not rename it. `updatedAt` advances only on conversation activity, including rectification turns, choice, adopt, and stop. Opening, refresh, and metadata PATCH do not bump it. A `?c=` that is not on the loaded page is looked up with `GET /api/sessions/{id}` before anyone may say it was deleted. Locked by `frontend/tests/session-open-preserves-identity.test.ts` and `frontend/tests/session-lookup-unlisted.test.ts`.
 - **Request behavior:** existing sessions remain selectable for reading while a request is active; creating or sending another request stays locked until the active request settles.
@@ -335,7 +335,8 @@ The birth-time rectification session is the consultation transcript plus a house
 
 ### Sidebar shell
 
-- **Composition:** provider, fixed header, one scroll-owning content region, fixed footer, trigger, rail, and flexible chat inset.
+- **Composition:** provider, fixed header, one scroll-owning content region, fixed footer, trigger, rail, and flexible chat inset. `/`、`/chart`、`/ephemeris`、`/reports` share one `(app)` layout: one `SessionListProvider` and one `SidebarProvider`. The session list is fetched once per tab; walking between those four pages does not remount the sidebar or refetch `/api/sessions`.
+- **Home registers shell controls** (new chat, select session, rename, pin, archive, delete, account menu). The other three pages leave `controls` unset, so rows are links to `/?c=<id>`.
 - **Trigger placement:** the single visible collapse/expand trigger sits beside the active session title in the chat header. The sidebar brand row has no duplicate trigger.
 - **Desktop:** 288px expanded by default at 1024px and above; 64px collapsed icon rail.
 - **Tablet:** 64px collapsed by default from 768px through 1023px; 240px when expanded.