docs: add WebSockets and Socket.IO page to Stacks Blockchain API docs

[rafa-stacks]

Adds a new guide page, content/docs/en/apis/stacks-blockchain-api/websockets.mdx, documenting the Stacks Blockchain API's two real-time channels, and registers it in the section sidebar via meta.json.

The page covers:

• Overview: both channels (raw WebSockets at /extended/v1/ws speaking JSON-RPC 2.0, and Socket.IO on the API root), mainnet/testnet connection URLs, and a warning callout that pushed events are susceptible to re-orgs and shouldn't be treated as final.
• Using the API client library: connectWebSocketClient and StacksApiSocketClient examples from the @stacks/blockchain-api-client README, plus a table of all nine subscription methods across both clients.
• Connecting directly: the wire protocols for integrations that don't use the client library — JSON-RPC subscribe/unsubscribe methods with all event names and required params, and the Socket.IO topic scheme (subscriptions query param, subscribe/unsubscribe emits, dynamic topic names).

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
hiro-systems-docs	Ready	Preview	Aug 10, 2026 9:10pm