fix(scope): all pages react to company scope change via useScopeEffect

- Created useScopeEffect hook that auto-triggers reload on scope change
- Replaced useEffect([], []) with useScopeEffect in 20+ pages
- Risks/Reports/Dashboard also use useScopeEffect
- Removed redundant per-page useCompanyScope where only effect was needed

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

@@ -1,7 +1,8 @@
 "use client";
 
-import { useEffect, useState } from "react";
+import { useState } from "react";
 import { listMajorEvents, listInquiries } from "@/lib/api-v2";
+import { useScopeEffect } from "@/lib/company-scope";
 import { PageContainer, Badge } from "@/components/shared/PageContainer";
 import { LoadingSpinner } from "@/components/shared/LoadingSpinner";
 import { EmptyState } from "@/components/shared/EmptyState";
@@ -26,7 +27,7 @@ export default function EventsPage() {
   const [isLoading, setIsLoading] = useState(true);
   const [tab, setTab] = useState<"events" | "inquiries">("events");
 
-  useEffect(() => {
+  useScopeEffect(() => {
     Promise.all([listMajorEvents(), listInquiries()])
       .then(([e, i]) => {
         setEvents((e.data as MajorEvent[]) ?? []);
@@ -37,7 +38,7 @@ export default function EventsPage() {
         setInquiries([]);
       })
       .finally(() => setIsLoading(false));
-  }, []);
+  });
 
   return (
     <PageContainer title="重大事项 & 追问清单" description="AI 从月报/弱信号中自动识别重大事项 + 生成追问清单">