feat(05-03): policy-level BudgetSummary, incident-based BudgetAlertBanner, AgentEditor policy wiring

- BudgetSummary shows policy-level utilization bars when companyId provided, falls back to agent-level
- BudgetAlertBanner loads open incidents for policy-based alerts (warn_threshold/hard_stop), falls back to agent thresholds
- AgentEditor reads budget from budget_policies and writes budget as policy on save (D-11)
- Dashboard passes companyId through to BudgetAlertBanner

src/renderer/components/dashboard/Dashboard.tsx

@@ -30,6 +30,7 @@ import { BudgetAlertBanner } from "./BudgetAlertBanner";
 
 export interface DashboardProps {
   companyName?: string;
+  companyId?: string;
   agents: AgentRecord[];
   tasks: TaskRecord[];
   runs: RunRecord[];
@@ -44,7 +45,7 @@ export interface DashboardProps {
 
 export function Dashboard(props: DashboardProps) {
   const t = useT();
-  const { companyName, agents, tasks, runs, approvals, activity, costs, messages = [], onNavigate } = props;
+  const { companyName, companyId, agents, tasks, runs, approvals, activity, costs, messages = [], onNavigate } = props;
 
   const agentMap = useMemo(() => new Map(agents.map((a) => [a.id, a])), [agents]);
   const taskMap = useMemo(() => new Map(tasks.map((t) => [t.id, t])), [tasks]);
@@ -95,7 +96,7 @@ export function Dashboard(props: DashboardProps) {
 
       {/* Conditional banners */}
       <RecoveryBanner />
-      <BudgetAlertBanner agents={agents} onNavigate={onNavigate} />
+      <BudgetAlertBanner agents={agents} onNavigate={onNavigate} companyId={companyId} />
 
       {/* Key Metrics — 4 cards */}
       <div className="grid grid-cols-2 gap-3 lg:grid-cols-4">