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)/pre-mortems/page.tsx

@@ -1,6 +1,7 @@
 "use client";
 
-import { useEffect, useState } from "react";
+import { useState } from "react";
+import { useScopeEffect } from "@/lib/company-scope";
 import {Sparkles } from "lucide-react";
 import { listPreMortems, runPreMortem, listRedTeams, runRedTeam } from "@/lib/api-v2";
 import { PageContainer, Card, Badge } from "@/components/shared/PageContainer";
@@ -33,7 +34,7 @@ export default function PreMortemsPage() {
   const [input, setInput] = useState("");
   const [perspective, setPerspective] = useState("competitor");
 
-  useEffect(() => {
+  useScopeEffect(() => {
     Promise.all([listPreMortems(), listRedTeams()])
       .then(([pm, rt]) => {
         setPreMortems((pm.data as PreMortemItem[]) ?? []);
@@ -44,7 +45,7 @@ export default function PreMortemsPage() {
         setRedTeams([]);
       })
       .finally(() => setIsLoading(false));
-  }, []);
+  });
 
   const handleRun = async () => {
     if (!input.trim()) {