feat: complete v0.5 operations foundation

app/api/sync/webhook/[sourceId]/[secret]/route.ts

@@ -1,6 +1,8 @@
 import { NextResponse } from "next/server";
 import { db } from "@/lib/db";
 import { withinRateLimit } from "@/lib/rate-limit";
+import { clientIp } from "@/lib/security";
+import { logEvent } from "@/lib/observability";
 import { webhookSecretMatches } from "@/lib/webhook";
 import { queuePull } from "@/lib/sync";
 
@@ -9,11 +11,11 @@ export async function POST(request: Request, { params }: { params: Promise<{ sou
   const id = Number(sourceId);
   const source = db.prepare("SELECT id, webhook_secret_hash FROM sources WHERE id=? AND is_enabled=1").get(id) as { id: number; webhook_secret_hash: string | null } | undefined;
   if (!source || !webhookSecretMatches(secret, source.webhook_secret_hash)) return NextResponse.json({ error: "Not found" }, { status: 404 });
-  const forwarded = request.headers.get("x-forwarded-for")?.split(",")[0].trim() || "unknown";
-  if (!withinRateLimit(`webhook:${id}:${forwarded}`)) return NextResponse.json({ error: "Too many requests" }, { status: 429 });
+  if (!withinRateLimit(`webhook:${id}:${clientIp(request)}`, 30, 60_000)) return NextResponse.json({ error: "Too many requests" }, { status: 429 });
   let payload: unknown = {};
   try { payload = await request.json(); } catch { /* Memos payload is optional; a pull reconciles source state. */ }
   db.prepare("UPDATE sources SET last_webhook_at=CURRENT_TIMESTAMP WHERE id=?").run(id);
   const queued = queuePull(id, "webhook", payload);
+  logEvent("info", "webhook_received", { sourceId: id, queued });
   return NextResponse.json({ ok: true, queued });
 }