WS-2284 - Fix lost view events in Optimizely

[louisearchibald]

Resolves JIRA: WS-2284

Summary

Attempts to solve a known bug with page-views firing incorrectly before experiments activate.

Code changes

• Adds an external store for activated Optimizely experiment flags and uses useSyncExternalStore so React components will re-render when new flags are activated.
• Provides a subscription model for React components, using a useActivatedExperiments hook.
• Uses new Set instances when updating snapshots so React reliably detects state changes.
• Add resetDecisionStore to clear state and reset snapshots.
• Registers a global DECISION notification listener to react to experiment activations.
• Calls notifyDecision(flagKey) to record activated experiments and notify subscribers.

Testing

1. We will test with an AA experiment set.up in Optimizely to verify that page-views are being recorded accurately.

[Copilot]

Pull request overview

This PR addresses lost Optimizely page-view events by ensuring tracking in OptimizelyPageMetrics only renders after the user is confirmed to be bucketed into a relevant experiment, including handling late experiment assignment via an Optimizely decision notification listener.

Changes:

• Adds @optimizely/optimizely-sdk to access Optimizely enums for notification types.
• Adds an initial decideAll-based membership check before rendering tracking components.
• Attaches and cleans up a decision notification listener to detect post-load bucketing into relevant experiments.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/app/components/OptimizelyPageMetrics/index.tsx	Adds initial bucketing check and a decision notification listener to gate tracking rendering until experiment membership is confirmed.
package.json	Adds a direct dependency on @optimizely/optimizely-sdk for notification enums.
yarn.lock	Updates lockfile to reflect the added Optimizely SDK dependency/version resolution.

ACtually just noticed something with the bundle size