`typicalTraffic` feature flag

## Feature Description

This issue adds `typicalTraffic` to the plugin's list of feature flags.

Link to the design doc: https://docs.google.com/document/d/1dsEs6-NjlP_LNqz5md5fnJMuxh9Vd9f88w4DTrZdLok/edit?tab=t.y7e2u5h52vf1

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## Acceptance criteria

* `typicalTraffic` is added to the plugin's available feature flags.

## Implementation Brief

* [ ] In `feature-flags.json`:
* Add `typicalTraffic` to the array, after `trafficOverview`.

### Test Coverage

* N/A

## QA Brief

*

## Changelog entry

*

Open feature-flags.json and locate the array containing trafficOverview. Add typicalTraffic immediately after it, then verify the file remains valid and the acceptance criterion is met; no test coverage is specified for this change.

Written by the indexing model from the issue text.