Fix renderUsername type for strictFunctionTypes compatibility

[dannyDotDev]

Summary

• Fix TypeScript error when strictFunctionTypes is enabled (e.g. Expo's default tsconfig)
• renderUsername prop in BubbleProps is typed as (user?: TMessage['user']) => ReactNode, but gets passed to renderComponentOrElement which expects (props: TProps) => ReactNode where TProps extends Record<string, any>
• With strict function types, the optional parameter creates a contravariance mismatch

The Error

error TS2345: Argument of type '(user?: TMessage["user"] | undefined) => ReactNode'
is not assignable to parameter of type '... | ((props: Record<string, any>) => ReactNode) | ...'

At src/Bubble/index.tsx:296:

return renderComponentOrElement(renderUsername, currentMessage.user)

Fix

One-line change in src/Bubble/types.ts:

- renderUsername?: (user?: TMessage['user']) => React.ReactNode
+ renderUsername?: (props: TMessage['user']) => React.ReactNode

The parameter was already always called with currentMessage.user (never undefined), so making it required matches actual usage. This is similar to the fixes in #2698.

Test

• Verified typecheck passes with strictFunctionTypes: true and strictNullChecks: true
• No runtime behavior change — just a type signature correction