fix(webhooks): restrict health route to internal service-binding calls

The public webhook host (webhooks.trycheatcode.com) served /health
unauthenticated and unrate-limited, exposing releaseSha and versionId with no
public consumer: the only caller is the gateway's release aggregation, which
probes https://webhooks.internal/health over the WEBHOOKS service binding.

Gate the route on the internal hostname and answer c.notFound() on any other
host, indistinguishable from a nonexistent route. Same posture as the
preview-proxy public health removal (#103): every public route must have a
named external consumer. Gateway is unchanged and its binding fetch already
carries the internal hostname, so there is no deploy-order skew.

Author: iamjr15

apps/webhooks-worker/README.md

@@ -137,7 +137,9 @@ The handler therefore resolves that Composio-project-global ID through the datab
 primary key; ownership and toolkit assignment are immutable after insertion,
 and terminal status changes atomically reconcile the user's active default.
 
-Production binds one immutable `CHEATCODE_RELEASE_SHA`, exposed by `/health`.
+Production binds one immutable `CHEATCODE_RELEASE_SHA`, exposed by `/health`
+only to the gateway's service-binding probe (`https://webhooks.internal/health`);
+on the public webhook host the route answers as not found.
 HTTP, cron, idempotency, deletion, and workflow continuation paths use their
 normal durable ownership and idempotency contracts; database migrations retain
 their separate target, role, lock, and schema validation.

apps/webhooks-worker/src/index.ts

@@ -165,14 +165,20 @@ webhooksApp.use(
   }),
 );
 
-webhooksApp.get("/health", (c) =>
-  c.json({
+webhooksApp.get("/health", (c) => {
+  // Service-binding-only surface: the gateway probes https://webhooks.internal/health
+  // for release aggregation. The public webhook host must answer like the route does
+  // not exist so release metadata never leaks on an unauthenticated endpoint.
+  if (new URL(c.req.url).hostname !== "webhooks.internal") {
+    return c.notFound();
+  }
+  return c.json({
     ok: true,
     releaseSha: c.env.CHEATCODE_RELEASE_SHA ?? "development",
     versionId: c.env.CF_VERSION_METADATA?.id ?? null,
     worker: "webhooks",
-  }),
-);
+  });
+});
 
 webhooksApp.post("/clerk", async (c) => {
   const signingSecret = await clerkWebhookSigningSecret(c.env);