fix: store context parameter in initialize for segment evaluation

[enf0rc3]

Background

We identified a race condition during between setProviderAndWait and setContext for segment-based targeting.

The race condition happened like this:

1. await OpenFeature.setProviderAndWait(provider) - provider becomes READY, this.context is {}
2. await OpenFeature.setContext({serverUri: ...}) - calls onContextChange, sets this.context

Between steps 1 and 2, the provider is READY and React hooks immediately evaluate flags.

The React SDK's useBooleanFlagValue hook attaches ContextChanged event handlers in useEffect (which runs after render).

If the ContextChanged event from step 2 fires before useEffect attaches handlers, the hook never re-evaluates.

The initial evaluation uses this.context = {}, so matchesSegment() returns false and the toggle appears disabled.

So in summary, it fixes these 2 bugs.

1. Library bug: initialize() ignored the context parameter entirely, so this.context was always {} regardless of how you called the SDK
2. Race condition: The consumer code called setContext after setProviderAndWait, creating a window where evaluations happen with no context

Because of the library bug even using "correct" calling order of (setting context before the provider) didn't work - the context was passed to initialize but thrown away.

Result

• Updated initialize() to take a context parameter passed by the OpenFeature SDK and update the context
• Updated README examples to show the correct calling patterns

[dylanlerch]

Changes look good, tests are amazing. Thanks for finding this.

Just a request for some changes to simplify the docs. I can sort these changes if you want, just let me know.