feat(dashboard): auto-compute risk scores + refresh button on Critical Gaps

- Auto-trigger POST /risk/compute on first load if no profiles exist
- Add "Refresh scores" button next to Critical Gaps header (spins while computing)
- Add computeRiskScores() to frontend/src/api/risk.ts
- After compute, invalidate risk-profiles query so table updates immediately

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/api/risk.ts

@@ -42,3 +42,9 @@ export async function getRiskProfile(techniqueId: string): Promise<RiskProfile>
   const { data } = await client.get<RiskProfile>(`/risk/profiles/${techniqueId}`);
   return data;
 }
+
+/** Trigger recomputation of all risk scores. */
+export async function computeRiskScores(): Promise<{ computed: number; skipped: number; errors: number; duration_seconds: number }> {
+  const { data } = await client.post("/risk/compute");
+  return data;
+}

frontend/src/pages/ExecutiveDashboardPage.tsx

@@ -1,4 +1,5 @@
-import { useQuery } from "@tanstack/react-query";
+import { useEffect } from "react";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
 import { useNavigate } from "react-router-dom";
 import {
   Loader2,
@@ -7,6 +8,7 @@ import {
   TrendingDown,
   Minus,
   ArrowRight,
+  RefreshCw,
 } from "lucide-react";
 import {
   LineChart,
@@ -28,7 +30,7 @@ import {
 import { getCoverageByTactic } from "../api/metrics";
 import { getThreatActors } from "../api/threat-actors";
 import { getTechniques, type TechniqueSummary } from "../api/techniques";
-import { getRiskProfiles, type RiskProfile } from "../api/risk";
+import { getRiskProfiles, computeRiskScores, type RiskProfile } from "../api/risk";
 
 // ── Score Gauge Component ────────────────────────────────────────────
 
@@ -163,11 +165,28 @@ export default function ExecutiveDashboardPage() {
     queryFn: () => getTechniques(),
   });
 
-  const { data: riskProfiles } = useQuery({
+  const queryClient = useQueryClient();
+
+  const { data: riskProfiles, isLoading: loadingRisk } = useQuery({
     queryKey: ["risk-profiles-exec"],
     queryFn: () => getRiskProfiles({ limit: 500 }),
   });
 
+  const computeMutation = useMutation({
+    mutationFn: computeRiskScores,
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["risk-profiles-exec"] });
+    },
+  });
+
+  // Auto-compute on first load if no profiles exist
+  useEffect(() => {
+    if (!loadingRisk && riskProfiles !== undefined && riskProfiles.length === 0) {
+      computeMutation.mutate();
+    }
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [loadingRisk, riskProfiles?.length]);
+
   const isLoading = loadingScore || loadingMetrics;
 
   if (isLoading) {
@@ -420,9 +439,24 @@ export default function ExecutiveDashboardPage() {
 
       {/* Section 6: Critical Gaps */}
       <div className="rounded-xl border border-gray-800 bg-gray-900 p-4">
-        <h2 className="mb-3 text-sm font-semibold text-gray-300">
-          Critical Gaps — Top 10 by Risk Priority
-        </h2>
+        <div className="mb-3 flex items-center justify-between">
+          <h2 className="text-sm font-semibold text-gray-300">
+            Critical Gaps — Top 10 by Risk Priority
+          </h2>
+          <button
+            onClick={() => computeMutation.mutate()}
+            disabled={computeMutation.isPending}
+            className="flex items-center gap-1.5 rounded-lg border border-gray-700 bg-gray-800 px-2.5 py-1 text-xs text-gray-400 hover:text-cyan-400 hover:border-cyan-500/30 disabled:opacity-50 transition-colors"
+            title="Recompute risk scores"
+          >
+            {computeMutation.isPending ? (
+              <Loader2 className="h-3 w-3 animate-spin" />
+            ) : (
+              <RefreshCw className="h-3 w-3" />
+            )}
+            {computeMutation.isPending ? "Computing…" : "Refresh scores"}
+          </button>
+        </div>
         <div className="overflow-x-auto">
           <table className="w-full text-sm">
             <thead>