feat: display platform agent status and version

prisma/migrations/20260806143000_add_platform_agent_version/migration.sql

@@ -0,0 +1,11 @@
+ALTER TABLE "provisioned_devices"
+ADD COLUMN "agent_version" TEXT,
+ADD COLUMN "agent_updated_at" TIMESTAMPTZ(3),
+ADD COLUMN "agent_last_seen_at" TIMESTAMPTZ(3);
+
+CREATE INDEX "provisioned_devices_agent_last_seen_at_idx"
+ON "provisioned_devices"("agent_last_seen_at");
+
+COMMENT ON COLUMN "provisioned_devices"."agent_version" IS '에이전트가 마지막으로 보고한 실행 버전';
+COMMENT ON COLUMN "provisioned_devices"."agent_updated_at" IS '현재 에이전트 버전이 처음 보고된 시각';
+COMMENT ON COLUMN "provisioned_devices"."agent_last_seen_at" IS '에이전트 시작 시 업데이트 확인을 마지막으로 수행한 시각';

prisma/schema.prisma

@@ -216,6 +216,9 @@ model ProvisionedDevice {
   kernel            String?
   distro            String?
   device            Json?
+  agentVersion      String?  @map("agent_version")
+  agentUpdatedAt    DateTime? @map("agent_updated_at") @db.Timestamptz(3)
+  agentLastSeenAt   DateTime? @map("agent_last_seen_at") @db.Timestamptz(3)
   installedAt       DateTime @default(now()) @map("installed_at") @db.Timestamptz(3)
   lastProvisionedAt DateTime @default(now()) @map("last_provisioned_at") @db.Timestamptz(3)
   createdAt         DateTime @default(now()) @map("created_at") @db.Timestamptz(3)
@@ -224,6 +227,7 @@ model ProvisionedDevice {
   @@unique([accountEmail, tailscaleHostname])
   @@index([accountEmail])
   @@index([tailscaleHostname])
+  @@index([agentLastSeenAt])
   @@map("provisioned_devices")
 }