fix: send mcp-server-cloudflare/<server> User-Agent on every outbound Cloudflare request

[mattzcarey]

None of this repo's outbound requests to Cloudflare set a User-Agent, so the API couldn't tell this traffic apart. Each server now sends User-Agent: mcp-server-cloudflare/<serverId> (for example, mcp-server-cloudflare/workers-bindings), so traffic can be broken down by server.

// Each app names itself (serverId = its apps/ directory name)
const app = createAuthenticatedMcpApp<Env>({
	serverId: 'workers-bindings',
	serviceHostnames: ['bindings-staging.mcp.cloudflare.com', 'bindings.mcp.cloudflare.com'],
	// ...
})

// packages/mcp-common/src/user-agent.ts
export function cloudflareFetch(input: RequestInfo | URL, init?: RequestInit<RequestInitCfProperties>) {
	const headers = new Headers(init?.headers ?? (input instanceof Request ? input.headers : undefined))
	headers.set('User-Agent', getUserAgent()) // mcp-server-cloudflare/<serverId>
	return fetch(input, { ...init, headers })
}

• serverId is required. The app factory passes it to setUserAgentServer() once, when the module loads. It must be lowercase kebab-case.

Path	Change
Cloudflare SDK (getCloudflareClient)	defaultHeaders: { 'User-Agent': getUserAgent() } replaces the SDK's own UA
fetchCloudflareApi	cloudflareFetch
OAuth code exchange + refresh (dash.cloudflare.com/oauth2/token)	cloudflareFetch
Identity probe (/user, /accounts)	cloudflareFetch
Direct fetch in Radar, URL Scanner, GraphQL, DEX WARP diag, Blog, docs guide/prompt	cloudflareFetch

• If a caller passes its own User-Agent, cloudflareFetch replaces it.