TIME TRAVELING TECH: NEW METRIC SET TO REVOLUTIONIZE EVENT SUBSCRIPTION MONITORING

Developers unveil groundbreaking timestamp feature to capture and analyze the age of events, paving the way for unprecedented insights in data flow.

Commit Details:

chore: add event timestamp metric for event subscription monitoring (#2391) This will help us understand if hub are sending events from far back in time. ## 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 introduces an event timestamp metric for monitoring event subscriptions in the `EventStreamHubSubscriber` class. It enhances the telemetry by adding the earliest event timestamp and associates the metrics with the `hub` property. ### Detailed summary - Added a new private property `hub` to store the hub client host. - Extracted the earliest event timestamp using `extractEventTimestamp` and recorded it with `statsd.gauge`. - Updated existing metrics to include the `hub` property for better context in monitoring. > ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}` <!-- end pr-codex -->