fix: use mutiple connections for ws subscriptions

[bmuddha]

This fix rewrites the way account subscriptions work in the cloning pipeline, instead of using a single connection per shard, we now use pool of connections, which are used to distribute subscriptions, giving us more subscription capacity, before threshold imposed by RPC provider is reached.

closes gh-362

Greptile Summary

This PR implements a WebSocket connection pool for account subscriptions to increase capacity before hitting RPC provider limits. The changes replace single-connection architecture with a distributed approach.

• Added PubsubPool in remote_account_updates_shard.rs to manage multiple WebSocket connections (8 per RPC upstream)
• Modified test setup in remote_account_updates.rs to include 5-second delay for connection establishment
• Added connection tracking and subscription distribution logic across pool
• Uses unsafe transmute for stream lifetime extension which should be reviewed carefully
• Implements proper cleanup of subscriptions and connections during shutdown

[greptile-apps]

_{2 file(s) reviewed, 5 comment(s)
Edit PR Review Bot Settings | Greptile}