refactor(home): let useSessionManagement own six session states

5.4: sessionsCursor / showArchivedSessions / sessionMenuId /
pendingSessionDeletion / sessionDetailLoadingId / sessionFullPrompt move into
use-session-management.ts, which now also computes visibleSessions from the
archived flag it owns. Home reads back only what its own JSX renders.

sessions / activeSessionId / creatingSession / pendingSessionId stay in the
shell: each is read by the bootstrap effect or the consultation run before the
session hook is called. Reasons are listed one by one in the progress record.

useSessionManagement params 41 -> 34, useProfileOnboarding 38 -> 26.

The growth contract tightens to useState 36 / useRef 37 / lines 1846 and gains an
assertion that useSessionManagement still runs before useRectificationSurface,
with the opener handed over through rectificationSessionOpenerRef.

Zero behavior change, zero copy change.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JUei7K13cYxLHE3Axe4A45

frontend/src/app/page.tsx

@@ -77,7 +77,6 @@ import {
 } from "@/hooks/use-rectification-surface";
 import { useSynastry } from "@/hooks/use-synastry";
 import { useSessionManagement } from "@/hooks/use-session-management";
-import { sortSessions } from "@/lib/session-groups";
 import { showChatNotice as setComposerNotice } from "@/lib/chat-notice";
 import { chatReplyAnnouncement, type ChatReplyPhase } from "@/lib/chat-reply-announcement";
 import {
@@ -252,10 +251,6 @@ export default function Home() {
   const [accountError, setAccountError] = useState("");
   const [signingOut, setSigningOut] = useState(false);
   const [sessions, setSessions] = useState<ChatSession[]>([]);
-  const [showArchivedSessions, setShowArchivedSessions] = useState(false);
-  const [sessionsCursor, setSessionsCursor] = useState<string | null>(null);
-  const [sessionMenuId, setSessionMenuId] = useState<string | null>(null);
-  const [pendingSessionDeletion, setPendingSessionDeletion] = useState<ChatSession | null>(null);
   const [modelCatalog, setModelCatalog] = useState<PublicLanguageModelCatalog | null>(null);
   const [activeSessionId, setActiveSessionId] = useState("");
   const draftTheme = useRef<Theme | null>(null);
@@ -295,8 +290,6 @@ export default function Home() {
   const prepareStartedAt = useRef<number | null>(null);
   const [guidedJourneyPreview, setGuidedJourneyPreview] = useState(false);
   const [creatingSession, setCreatingSession] = useState(false);
-  const [sessionDetailLoadingId, setSessionDetailLoadingId] = useState<string | null>(null);
-  const [sessionFullPrompt, setSessionFullPrompt] = useState<{ question: string; theme: Theme } | null>(null);
   const [onboardingStep, setOnboardingStep] = useState<OnboardingStep>("name");
   const [onboardingJustCompleted, setOnboardingJustCompleted] = useState(false);
   const [onboardingPaywallOpen, setOnboardingPaywallOpen] = useState(false);
@@ -390,11 +383,6 @@ export default function Home() {
   const activeRectificationSession = activeSession?.sessionType === "birth_time_rectification";
   const rectificationSurfaceOpen = activeRectificationSession
     && activeSession.id === rectificationSessionId;
-  const visibleSessions = sortSessions(sessions.filter((session) => (showArchivedSessions ? session.archivedAt : !session.archivedAt)
-    && (session.sessionType === "birth_time_rectification"
-    || session.messages.length > 0
-    || !session.messagesHydrated
-    || session.id === activeSessionId)));
   const activeError = requestError && requestError.sessionId === activeSession?.id ? requestError.message : "";
   const isLoading = pendingSessionId === activeSession?.id;
   const productEntrypointsDisabled = !hydrated
@@ -439,6 +427,15 @@ export default function Home() {
     ? "服务端未能读取完整出生资料，请重新确认并保存后再开始生时校正。"
     : rectificationError;
   const {
+    visibleSessions,
+    sessionsCursor,
+    setSessionsCursor,
+    showArchivedSessions,
+    sessionMenuId,
+    setSessionMenuId,
+    pendingSessionDeletion,
+    setPendingSessionDeletion,
+    setSessionFullPrompt,
     updateSession,
     persistSession,
     ensureSessionMessages,
@@ -457,8 +454,7 @@ export default function Home() {
     rectificationSessionId, sessionDetailInFlight, sessionSelectionSource, sessions, sessionsRef,
     setActiveChartId, setActiveSessionId, setBirthTimeConsultationConsent, setCreatingSession,
     setDraft, setDraftEntrypoint, setDraftTheme, setRectificationError, setRectificationErrorSessionId, setRequestError,
-    setSessionDetailLoadingId, setSessionFullPrompt, setSessions, sessionsCursor, setSessionsCursor,
-    showArchivedSessions, setShowArchivedSessions, uiPreview, visibleSessions,
+    setSessions, uiPreview,
     openRectificationSession: (exactSessionId) => rectificationSessionOpenerRef.current(exactSessionId),
   });