refactor(dashboard): consolidate BudgetAlertBanner dual source into helper

src/renderer/lib/budget-alerts.ts

@@ -0,0 +1,70 @@
+import type { AgentRecord, BudgetIncidentRecord } from "@shared/types";
+
+export type BudgetAlertSeverity = "warn" | "danger";
+
+export interface BudgetAlert {
+  id: string;
+  severity: BudgetAlertSeverity;
+  title: string;
+  scopeLabel: string;
+  pct: number;
+  observedUsd: number;
+  limitUsd: number;
+}
+
+/**
+ * Unify policy-based BudgetIncidentRecord alerts and fallback agent-level
+ * threshold alerts into a single `BudgetAlert[]`.
+ *
+ * When `incidents` is non-empty, policy-based alerts are used exclusively.
+ * Otherwise we derive alerts from agents whose month-to-date spend crosses
+ * 80% of their monthly budget.
+ */
+export function computeBudgetAlerts(
+  incidents: BudgetIncidentRecord[],
+  agents: AgentRecord[],
+): BudgetAlert[] {
+  if (incidents.length > 0) {
+    return incidents.map((incident) => {
+      const pct = incident.amountLimit > 0
+        ? Math.round((incident.amountObserved / incident.amountLimit) * 100)
+        : 0;
+      const isHardStop = incident.thresholdType === "hard_stop";
+      const scopeLabel = getScopeLabel(incident.scopeType, incident.scopeId, agents);
+      return {
+        id: incident.id,
+        severity: isHardStop ? "danger" : "warn",
+        title: isHardStop ? "Budget Hard Stop" : "Budget Warning",
+        scopeLabel,
+        pct,
+        observedUsd: incident.amountObserved / 100,
+        limitUsd: incident.amountLimit / 100,
+      };
+    });
+  }
+
+  return agents
+    .filter((a) => a.budgetMonthlyUsd > 0 && a.spentMonthlyUsd / a.budgetMonthlyUsd >= 0.8)
+    .map((a): BudgetAlert => {
+      const pct = Math.round((a.spentMonthlyUsd / a.budgetMonthlyUsd) * 100);
+      return {
+        id: a.id,
+        severity: pct >= 100 ? "danger" : "warn",
+        title: "Budget Alert",
+        scopeLabel: a.name,
+        pct,
+        observedUsd: a.spentMonthlyUsd,
+        limitUsd: a.budgetMonthlyUsd,
+      };
+    })
+    .sort((a, b) => b.pct - a.pct);
+}
+
+function getScopeLabel(scopeType: string, scopeId: string, agents: AgentRecord[]): string {
+  if (scopeType === "company") return "Company";
+  if (scopeType === "agent") {
+    const agent = agents.find((a) => a.id === scopeId);
+    return agent ? agent.name : scopeId.slice(0, 8);
+  }
+  return scopeId.slice(0, 8);
+}