feat(scope): add company scope switcher — two views (by-task all companies / by-company all tasks)

- CompanyScopeContext + Provider with localStorage persistence
- Sidebar company selector (desktop + mobile)
- apiFetch auto-injects company_id on GET requests
- Dashboard summary API supports company_id filter
- Milestones/Financial/DigitalTwins pages use scope instead of manual input
- HealthHeatmap/HealthTrends components react to scope changes

frontend/src/components/dashboard/HealthHeatmap.tsx

@@ -2,6 +2,7 @@
 
 import { useEffect, useState } from "react";
 import { apiFetch } from "@/lib/api";
+import { useCompanyScope } from "@/lib/company-scope";
 import { LoadingSpinner } from "@/components/shared/LoadingSpinner";
 import { EmptyState } from "@/components/shared/EmptyState";
 import { DIMENSIONS_14 } from "@/components/health/HealthRadar";
@@ -29,18 +30,20 @@ const LINE_COLORS = [
 
 /** 健康度趋势对比图 — 按企业分组，每家企业一条折线。 */
 export function HealthTrends({ companyId }: { companyId?: string }) {
+  const { companyId: scopeCompanyId } = useCompanyScope();
+  const effectiveCompanyId = companyId ?? scopeCompanyId;
   const [data, setData] = useState<CompanyTrend[]>([]);
   const [loading, setLoading] = useState(true);
 
   useEffect(() => {
-    const path = companyId
-      ? `/dashboard/trends?company_id=${companyId}&months=6`
+    const path = effectiveCompanyId
+      ? `/dashboard/trends?company_id=${effectiveCompanyId}&months=6`
       : "/dashboard/trends?months=6";
     apiFetch<CompanyTrend[]>(path)
       .then((res) => setData((res.data as CompanyTrend[]) || []))
       .catch(() => {})
       .finally(() => setLoading(false));
-  }, [companyId]);
+  }, [effectiveCompanyId]);
 
   if (loading) return <LoadingSpinner />;
   if (!data.length) return <EmptyState title="暂无趋势数据" />;
@@ -156,6 +159,8 @@ export function HealthTrends({ companyId }: { companyId?: string }) {
   );
 }
 export function HealthHeatmap({ companyId }: { companyId?: string }) {
+  const { companyId: scopeCompanyId } = useCompanyScope();
+  const effectiveCompanyId = companyId ?? scopeCompanyId;
   const [data, setData] = useState<HeatmapRow[]>([]);
   const [loading, setLoading] = useState(true);
 
@@ -163,11 +168,11 @@ export function HealthHeatmap({ companyId }: { companyId?: string }) {
     apiFetch<HeatmapRow[]>("/dashboard/heatmap")
       .then((res) => {
         const rows = (res.data as HeatmapRow[]) || [];
-        setData(companyId ? rows.filter((r) => r.company_id === companyId) : rows);
+        setData(effectiveCompanyId ? rows.filter((r) => r.company_id === effectiveCompanyId) : rows);
       })
       .catch(() => {})
       .finally(() => setLoading(false));
-  }, [companyId]);
+  }, [effectiveCompanyId]);
 
   if (loading) return <LoadingSpinner />;
   if (!data.length) return <EmptyState title="暂无热力图数据" />;