fix(home): one new-chat intent and a scoped login-return stash (BUG-1038)

Coming back to / from /people could show the previous rectification session
as a locked page: its title in the header, the composer stuck on
"正在打开生时校正…", and the new-chat greeting in the middle.

The state that survived between pages is the sessionStorage login-return
stash that secondary-page sidebar links write from the current ?c=:
- /people「和 TA 对话」used a second intent (?newChat=1) parsed by a
  component mounted inside Home after bootstrap, so the bootstrap new-chat
  branch never ran and the stash won.
- A stash id not in the current person's loaded list was looked up and
  landed with urlAction "keep", which assumes ?c= is already in the address
  bar. It was not, so the rectification auto-open never fired. The stash
  also ignored which person was current.
- An in-page new chat left the stash in place.

Fix: delete NewChatDeepLink / ?newChat and route「和 TA 对话」through
newChatHref(); a looked-up stash writes ?c= back (replace-selected) and is
dropped when it belongs to another person; startNewChat and
openChatBoundToProfile clear the stash. ?c= deep links, BUG-989 and BUG-705
are unchanged.

Tests: new real-lifecycle suite mounting the real Home, sidebar and people
page (10 cases: four secondary pages + mobile drawer, 和 TA 对话 for self and
another person, out-of-scope stash, same-person stash beyond the first page,
in-page new chat), plus two contract/unit tests. Six fail on origin/staging,
all pass here. Full suite 3928 / 61 failing, failure names identical to the
0ab061b9 baseline (3916 / 61).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017eEAG8HD3mm8gsKXgk8uU8

frontend/src/app/(app)/page.tsx

@@ -45,7 +45,7 @@ import { composerDraftSnapshot, setComposerDraft } from "@/lib/composer-draft";
 import { sessionMatchesSubject } from "@/lib/chat-profile-picker-model";
 import { bindCurrentSubjectAccount, readCurrentSubjectId, useCurrentSubjectProfile } from "@/lib/current-subject";
 import { DailyStarlanguageBinder } from "@/components/daily-starlanguage-binder";
-import { NewChatDeepLink, SynastryDeepLink } from "@/components/people-home-links";
+import { SynastryDeepLink } from "@/components/people-home-links";
 import { StarterEntries, StarterGreeting } from "@/components/starter-home";
 import {
   GENERAL_NO_MINUTE_DAILY_FORTUNE_QUESTION,
@@ -1127,7 +1127,6 @@ export default function Home() {
           natalMinuteAvailable={natalMinuteAvailable}
           setDailyStarlanguage={setDailyStarlanguage}
         />
-        <NewChatDeepLink ready={Boolean(account && modelCatalog)} startNewChat={startNewChat} />
         <SynastryDeepLink profile={profile} draft={synastryPanel.draftSynastryQuestionFromChart} />
         <span className="sr-only" role="status" aria-live="polite" aria-atomic="true">{replyAnnouncement}</span>
         {pendingSessionDeletion ? (

frontend/src/components/people-home-links.tsx

@@ -2,7 +2,6 @@
 
 import { useEffect, useRef } from "react";
 
-import { useCurrentSubjectReady } from "@/lib/current-subject";
 import type { ChartLibraryRecord, Profile, SynastryRelationshipType } from "@/lib/home-types";
 
 function stripQuery(key: string) {
@@ -13,22 +12,6 @@ function stripQuery(key: string) {
   window.history.replaceState(null, "", `${window.location.pathname}${query ? `?${query}` : ""}${window.location.hash}`);
 }
 
-export function NewChatDeepLink(props: {
-  ready: boolean;
-  startNewChat: () => Promise<unknown>;
-}) {
-  const started = useRef(false);
-  const subjectReady = useCurrentSubjectReady();
-  useEffect(() => {
-    if (!props.ready || !subjectReady || started.current) return;
-    if (!new URLSearchParams(window.location.search).has("newChat")) return;
-    started.current = true;
-    stripQuery("newChat");
-    void props.startNewChat();
-  }, [props.ready, props.startNewChat, subjectReady]);
-  return null;
-}
-
 export function SynastryDeepLink(props: {
   profile: Profile;
   draft: (record: ChartLibraryRecord, relationshipType: SynastryRelationshipType) => Promise<void>;

frontend/src/components/people/people-page.tsx

@@ -3,6 +3,7 @@
 import { useEffect, useRef, useState, type Dispatch, type FormEvent, type SetStateAction } from "react";
 import { FileText, MessageSquareText, Orbit } from "lucide-react";
 
+import { newChatHref } from "@/lib/chat-session-url";
 import { effectiveBirthDate } from "@/lib/effective-birth-date";
 import { ChartProfileForm } from "@/components/chart-profile-form";
 import { SecondaryPageShell } from "@/components/secondary-page-shell";
@@ -434,7 +435,7 @@ export function PeopleArchiveView({
               <dd>{peopleAyanamsaLabel(selected.profile)}</dd>
             </dl>
             <div className="people-archive-actions">
-              <button type="button" onClick={() => openPerson(selected.id, "/?newChat=1")}>
+              <button type="button" onClick={() => openPerson(selected.id, newChatHref())}>
                 <MessageSquareText size={18} strokeWidth={1.75} aria-hidden="true" />和 TA 对话
               </button>
               <button type="button" onClick={() => openPerson(selected.id, "/chart")}>

frontend/src/hooks/use-session-management.ts

@@ -8,6 +8,7 @@ import { writeChatSession } from "@/lib/chat-session-write-contract";
 import {
   SESSION_LOOKUP_FAILED_NOTICE,
   SESSION_MISSING_NOTICE,
+  clearLoginSessionReturn,
   parseSessionUrlQuery,
   writeSessionUrl,
 } from "@/lib/chat-session-url";
@@ -348,6 +349,9 @@ export function useSessionManagement(params: SessionManagementParams) {
     pendingCreateById.current.set(nextSession.id, {
       continuedFromSessionId: options?.continuedFromSessionId,
     });
+    // A new chat is not a place to come back to (BUG-1038): drop the stashed
+    // `?c=` a secondary-page link left, or the next bare `/` reopens it.
+    clearLoginSessionReturn();
     setSessions((current) => replaceUnsavedEmptyConsultations(current, nextSession));
     setActiveSessionId(nextSession.id);
     setDraft("");
@@ -617,6 +621,7 @@ export function useSessionManagement(params: SessionManagementParams) {
       if (isUnsavedEmptyConsultation(existing)) pendingCreateById.current.delete(existing.id);
     }
     pendingCreateById.current.set(nextSession.id, {});
+    clearLoginSessionReturn();
     setSessions((current) => replaceUnsavedEmptyConsultations(current, nextSession));
     setActiveSessionId(nextSession.id);
     setDraft("");

frontend/src/lib/chat-session-url.ts

@@ -17,6 +17,12 @@ export type BootstrapSessionSelection = {
   readonly clearStoredReturn: boolean;
 };
 
+/**
+ * The one new-chat intent. The read-only sidebar and /people「和 TA 对话」 both
+ * link here; the person rides on the current-subject store, not the URL.
+ * Bootstrap turns it into a local empty consultation and ignores (then clears)
+ * the stashed `?c=` return, so no older session is reopened (BUG-1015/1038).
+ */
 export function newChatHref(): string {
   return "/?new=1";
 }
@@ -147,15 +153,32 @@ export function resolveBootstrapSessionSelection(input: {
   };
 }
 
+/**
+ * `origin` says where the looked-up id came from. A `?c=` is already in the
+ * address bar, so a found session keeps it. A stashed return (the `?c=` a
+ * secondary-page link left behind) is not: landing on it must write it back,
+ * or the page shows that session without the URL that opens it — for a
+ * rectification session that is a locked composer that never opens (BUG-1038).
+ * A stashed session of another person is not a place to return to at all.
+ */
 export function bootstrapSelectionFromLookup(
-  status: "found" | "missing" | "unavailable",
+  status: "found" | "missing" | "unavailable" | "other-subject",
   requestedId: string,
   defaultSessionId: string,
+  origin: "url" | "stored-return" = "url",
 ): BootstrapSessionSelection {
   if (status === "found") {
     return {
       sessionId: requestedId,
-      urlAction: "keep",
+      urlAction: origin === "stored-return" ? "replace-selected" : "keep",
+      missing: false,
+      clearStoredReturn: true,
+    };
+  }
+  if (status === "other-subject") {
+    return {
+      sessionId: defaultSessionId,
+      urlAction: "none",
       missing: false,
       clearStoredReturn: true,
     };

frontend/src/lib/home-bootstrap-run.ts

@@ -44,6 +44,7 @@ import {
 } from "@/lib/home-cloud-sync";
 import { chartSnapshotForSession, missingProfileStep, readProfile } from "@/lib/home-profile";
 import { peekSubjectCatalog, readCurrentSubjectId } from "@/lib/current-subject";
+import { sessionMatchesSubject } from "@/lib/chat-profile-picker-model";
 import {
   emptyProfile,
   pendingConsultationStorageKey,
@@ -351,6 +352,7 @@ export async function resolveLanding(
     catalog: ready.nextModelCatalog,
     defaultSessionId: ready.nextSessions[0].id,
     signal,
+    inSubjectScope: (session) => sessionMatchesSubject(session, readCurrentSubjectId()),
   });
   let nextSessions = lookedUp.sessions;
   const bootstrapSelection: BootstrapSessionSelection = lookedUp.selection;

frontend/src/lib/home-cloud-sync.ts

@@ -1,6 +1,7 @@
 import { writeChatSession } from "@/lib/chat-session-write-contract";
 import {
   bootstrapSelectionFromLookup,
+  parseSessionUrlQuery,
   persistLoginSessionReturn,
   readLoginSessionReturn,
   resolveBootstrapSessionSelection,
@@ -514,6 +515,8 @@ export async function resolveLookupBootstrap(input: {
   defaultSessionId: string;
   catalog: PublicLanguageModelCatalog | null;
   signal?: AbortSignal;
+  /** Current person's scope. A stashed return outside it is dropped, not reopened. */
+  inSubjectScope?: (session: ChatSession) => boolean;
 }): Promise<{
   selection: BootstrapSessionSelection;
   sessions: ChatSession[];
@@ -529,11 +532,19 @@ export async function resolveLookupBootstrap(input: {
   if (selection.urlAction !== "lookup") {
     return { selection, sessions: input.sessions, notice: null };
   }
+  const origin = parseSessionUrlQuery(window.location.search).present ? "url" : "stored-return";
   const looked = await lookupSessionById(selection.sessionId, input.catalog, input.signal);
   throwIfAborted(input.signal);
   if (looked.status === "found") {
+    if (origin === "stored-return" && input.inSubjectScope && !input.inSubjectScope(looked.session)) {
+      return {
+        selection: bootstrapSelectionFromLookup("other-subject", looked.session.id, input.defaultSessionId, origin),
+        sessions: input.sessions,
+        notice: null,
+      };
+    }
     return {
-      selection: bootstrapSelectionFromLookup("found", looked.session.id, input.defaultSessionId),
+      selection: bootstrapSelectionFromLookup("found", looked.session.id, input.defaultSessionId, origin),
       sessions: mergeHydratedSession(input.sessions, looked.session),
       notice: null,
     };