feat: add configurable infrastructure alerts

api/prisma/schema.prisma

@@ -2432,3 +2432,17 @@ model SecurityProtectedNetwork {
 
   @@index([enabled, createdAt])
 }
+
+model InfrastructureAlertSetting {
+  id                  String    @id @default("global")
+  configVersion       Int       @default(1)
+  effectiveVersion    Int       @default(1)
+  thresholds          Json
+  effectiveThresholds Json
+  applyStatus         String    @default("effective")
+  lastError           String?
+  updatedById         String?
+  appliedAt           DateTime?
+  createdAt           DateTime  @default(now())
+  updatedAt           DateTime  @updatedAt
+}