Revert "fix: accept SDK provider capability headers"

This reverts commit e7ad5580ec.

hub/test/unit/provider-proxy.test.ts

@@ -107,33 +107,6 @@ describe("run-scoped provider proxy", () => {
     expect(diagnostics).toEqual([{ code: "provider_proxy_unauthorized", category: "authorization" }]);
   });
 
-  it("accepts the run capability in the Anthropic x-api-key header", async () => {
-    let upstreamRequests = 0;
-    const upstream = createServer((_request, response) => {
-      upstreamRequests += 1;
-      response.writeHead(200, { "content-type": "application/json" });
-      response.end(JSON.stringify({ ok: true }));
-    });
-    upstreamServers.push(upstream);
-    upstream.listen(0, "127.0.0.1");
-    await once(upstream, "listening");
-    const address = upstream.address();
-    if (address === null || typeof address === "string") throw new Error("expected upstream TCP address");
-    const lease = await openProviderProxyLease({
-      baseUrl: `http://127.0.0.1:${address.port}`,
-      authToken: "customer-secret",
-      anthropicApiKey: "",
-    });
-    leases.push(lease);
-
-    const response = await fetch(`${lease.sdkEnv.ANTHROPIC_BASE_URL}/v1/messages`, {
-      headers: { "x-api-key": lease.sdkEnv.ANTHROPIC_AUTH_TOKEN ?? "" },
-    });
-
-    expect(response.status).toBe(200);
-    expect(upstreamRequests).toBe(1);
-  });
-
   it("does not forward provider credentials across an upstream redirect", async () => {
     let redirectedRequests = 0;
     const diagnostics: unknown[] = [];