feat: expose health probes and metrics

app/api/health/route.ts

@@ -2,10 +2,12 @@ import { NextResponse } from "next/server";
 import { db } from "@/lib/db";
 
 export const dynamic = "force-dynamic";
-export async function GET() {
+export async function GET(request: Request) {
+  const probe = new URL(request.url).searchParams.get("probe");
+  if (probe === "live") return NextResponse.json({ ok: true, status: "live", version: process.env.APP_VERSION || "development", timestamp: new Date().toISOString() });
   try {
     db.prepare("SELECT 1").get();
     const failedJobs = Number((db.prepare("SELECT count(*) AS count FROM sync_jobs WHERE status='failed'").get() as { count: number }).count);
-    return NextResponse.json({ ok: true, version: process.env.APP_VERSION || "development", database: "ok", failedJobs, timestamp: new Date().toISOString() });
+    return NextResponse.json({ ok: true, status: "ready", version: process.env.APP_VERSION || "development", database: "ok", failedJobs, timestamp: new Date().toISOString() });
   } catch { return NextResponse.json({ ok: false, database: "error" }, { status: 503 }); }
 }