feat: turbostarter boilerplate

Production-ready Next.js boilerplate with:
- Runtime env validation (fail-fast on missing vars)
- Feature-gated config (S3, Stripe, email, OAuth)
- Docker + Coolify deployment pipeline
- PostgreSQL + pgvector, MinIO S3, Better Auth
- TypeScript strict mode (no ignoreBuildErrors)
- i18n (en/es), AI modules, billing, monitoring

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/api/src/utils/on-error.ts

@@ -0,0 +1,76 @@
+import * as z from "zod";
+
+import { isKey } from "@turbostarter/i18n";
+import { getTranslation } from "@turbostarter/i18n/server";
+import { captureException } from "@turbostarter/monitoring-web/server";
+import { HttpStatusCode } from "@turbostarter/shared/constants";
+import { logger } from "@turbostarter/shared/logger";
+import { getStatusCode } from "@turbostarter/shared/utils";
+
+import type { Context } from "hono";
+
+const errorSchema = z.object({
+  code: z.string().optional(),
+  message: z.string(),
+});
+
+const isError = (e: unknown): e is z.infer<typeof errorSchema> => {
+  return errorSchema.safeParse(e).success;
+};
+
+export const onError = async (
+  e: unknown,
+  c?: Context<{
+    Bindings: { NODE_ENV: string };
+    Variables: { locale: string };
+  }>,
+) => {
+  const { t, i18n } = await getTranslation({
+    locale: c?.var.locale,
+    request: c?.req.raw,
+  });
+
+  const status = getStatusCode(e);
+  const details = {
+    status,
+    headers: {
+      "Content-Type": "application/json",
+    },
+  };
+
+  const timestamp = new Date().toISOString();
+  const path = c?.req.raw.url ? new URL(c.req.raw.url).pathname : "/api";
+
+  if (status >= HttpStatusCode.INTERNAL_SERVER_ERROR) {
+    captureException(e, { path, status, timestamp });
+  }
+
+  if (isError(e)) {
+    logger.error(e.code, e.message);
+    return new Response(
+      JSON.stringify({
+        code: e.code,
+        message: e.message
+          ? e.message
+          : e.code && isKey(e.code, i18n)
+            ? t(e.code)
+            : ((e.message || e.code) ?? t("common:error.general")),
+        status,
+        timestamp,
+        path,
+      }),
+      details,
+    );
+  }
+
+  logger.error(e);
+  return new Response(
+    JSON.stringify({
+      code: "common:error.general",
+      message: t("common:error.general"),
+      status,
+      path,
+    }),
+    details,
+  );
+};