tracks repo metadata on first index, or on full reindex (when the
tantivy index hash is updated, for example), includes the following
info:

- repo ref
- repo provider
- size in bytes
- number of qdrant chunks
- time taken to index

sample event:

    RepoEvent {
        name: "index",
        payload: [
            ("repo_ref", String("nerdypepper/dijo")),
            ("provider", String("github")),
            ("file_count", Number(35)),
            ("chunk_count", Number(236)),
            ("bytes", String("116.59KB")),
            ("sync_time", String("4.957807429s")),
        ],
    }

---

to test this changeset, set the following values in `local_config.json`:

    {
        "analytics_key": "..",
        "analytics_data_plane": ".."
    }

run rudderstack in "live event stream" mode, and index a repository.

- marks full index resets as `SchemaUpgrade`s
- marks periodic reindex jobs as `PeriodicSync`s