fix(web): 会话列表合同跟着外壳搬家，无活跃会话不再静默吞发送

四条源码合同改到 (app)/layout 与注册载荷两端对断。列表只剩校正会话时普通输入框锁定，发送会打开校正或给出提示。

frontend/src/hooks/use-consultation-run.ts

@@ -64,6 +64,7 @@ import { completedOnboardingTranscript, isProfileComplete, selectedBirthPlace }
 import { pendingConsultationStorageKey, timestamp } from "@/lib/home-types";
 import {
   consultSendBlockedByRectificationSession,
+  missingActiveSessionSendAction,
   SESSION_NOT_CONSULTATION_CODE,
 } from "@/lib/rectification-session-composer-guard";
 import type {
@@ -514,7 +515,19 @@ export function useConsultationRun(params: ConsultationRunParams) {
       ? sessions.find((session) => session.id === targetSessionId)
       : activeSession;
     const currentSession = options.sessionOverride ?? liveSession;
-    if (!question || !currentSession || !modelCatalog || !account) return false;
+    if (!question) return false;
+    if (!currentSession) {
+      const action = missingActiveSessionSendAction(sessions);
+      if ("openSessionId" in action) {
+        setDraft(originalQuestion);
+        await openRectificationSession(action.openSessionId);
+        setDraft(originalQuestion);
+        return false;
+      }
+      setComposerNotice(action.notice);
+      return false;
+    }
+    if (!modelCatalog || !account) return false;
     if (consultSendBlockedByRectificationSession(currentSession)) {
       if (resuming) {
         pendingConsultation.current = null;