Fix Redis state typings for url and client options

[haydenbleasel]

Summary

• fix createRedisState typings so url appears in IntelliSense for createRedisState({ url: "..." })
• add an explicit factory options type and keep REDIS_URL env fallback
• support passing an existing Redis client and avoid closing caller-owned clients
• add tests for explicit url usage and existing-client usage
• include a patch changeset for @chat-adapter/state-redis

Test plan

• Ran pnpm build and pnpm test, both successful

[vercel]

@haydenbleasel is attempting to deploy a commit to the Vercel Labs Team on Vercel.

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[bensabic]

This looks good overall, but I think the injected redis client path in connect() needs one follow-up. Right now it treats client.isOpen as enough to mark the adapter connected, but in node-redis v5 isOpen only means the socket is open, not that the client is ready to accept commands. The docs distinguish this from client.isReady, and isOpen can still be true while the client is connecting or reconnecting. That means await adapter.connect() can resolve too early for createRedisState({ client }), and the first Redis command can still race startup/reconnect.

Could we gate on client.isReady or wait for the ready event in the already-open case, and add a test that covers an injected client that is open but not yet ready?