fix: make shard id required for the hub subscriber (#2623)

## Why is this change needed?
It's hard for the client to determine where to resume from if they're
subscribed to multiple shards.

## Merge Checklist

_Choose all relevant options below by adding an `x` now or at any time
before submitting for review_

- [x] PR title adheres to the [conventional
commits](https://www.conventionalcommits.org/en/v1.0.0/) standard
- [x] PR has a
[changeset](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#35-adding-changesets)
- [x] PR has been tagged with a change label(s) (i.e. documentation,
feature, bugfix, or chore)
- [ ] PR includes
[documentation](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#32-writing-docs)
if necessary.

<!-- start pr-codex -->

---

## PR-Codex overview
This PR focuses on making the `shardIndex` parameter required for the
`hubSubscriber` and removing the optional `totalShards` parameter. It
ensures that the `shardIndex` is always provided when creating instances
of `BaseHubSubscriber` and `EventStreamHubSubscriber`.

### Detailed summary
- Made `shardIndex` a required parameter in the constructors of
`BaseHubSubscriber` and `EventStreamHubSubscriber`.
- Removed the optional `totalShards` parameter from both constructors.
- Updated the constructor calls to reflect the removal of `totalShards`.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your
question}`

<!-- end pr-codex -->

.changeset/spotty-icons-move.md

@@ -0,0 +1,5 @@
+---
+"@farcaster/shuttle": patch
+---
+
+fix: make shard id required for the hub subscriber

packages/shuttle/src/shuttle/hubSubscriber.ts

@@ -59,24 +59,21 @@ export class BaseHubSubscriber extends HubSubscriber {
   protected eventTypes: HubEventType[];
 
   private stream: ClientReadableStream<HubEvent> | null = null;
-  private totalShards: number | undefined;
-  private shardIndex: number | undefined;
+  private shardIndex: number;
   private connectionTimeout: number; // milliseconds
 
   constructor(
     label: string,
     hubClient: HubRpcClient,
+    shardIndex: number,
     log: Logger,
     eventTypes?: HubEventType[],
-    totalShards?: number,
-    shardIndex?: number,
     connectionTimeout = 30000,
   ) {
     super();
     this.label = label;
     this.hubClient = hubClient;
     this.log = log;
-    this.totalShards = totalShards;
     this.shardIndex = shardIndex;
     this.eventTypes = eventTypes || DEFAULT_EVENT_TYPES;
     this.connectionTimeout = connectionTimeout;
@@ -120,7 +117,6 @@ export class BaseHubSubscriber extends HubSubscriber {
 
     const subscribeParams = {
       eventTypes: this.eventTypes,
-      totalShards: this.totalShards,
       shardIndex: this.shardIndex,
       fromId,
     };
@@ -131,7 +127,7 @@ export class BaseHubSubscriber extends HubSubscriber {
         this.log.info(
           `HubSubscriber ${this.label} subscribed to hub events (types ${JSON.stringify(this.eventTypes)}, shard: ${
             this.shardIndex
-          }/${this.totalShards})`,
+          })`,
         );
         this.stream = stream;
         this.stopped = false;
@@ -217,17 +213,16 @@ export class EventStreamHubSubscriber extends BaseHubSubscriber {
   constructor(
     label: string,
     hubClient: HubClient,
+    shardIndex: number,
     eventStream: EventStreamConnection,
     redis: RedisClient,
     shardKey: string,
     log: Logger,
     eventTypes?: HubEventType[],
-    totalShards?: number,
-    shardIndex?: number,
     connectionTimeout?: number,
     options?: EventStreamHubSubscriberOptions,
   ) {
-    super(label, hubClient.client, log, eventTypes, totalShards, shardIndex, connectionTimeout);
+    super(label, hubClient.client, shardIndex, log, eventTypes, connectionTimeout);
     this.eventStream = eventStream;
     this.redis = redis;
     this.streamKey = `hub:${hubClient.host}:evt:msg:${shardKey}`;