fix: accept IFlagsmithTrait in identify() traits, matching setTraits()

[chiliec]

What

flagsmith.identify() was typed as traits?: Record<T, IFlagsmithValue>, so passing a TraitEvaluationContext (e.g. { value: "abc", transient: true }) was a compile error even though setTraits() accepts Record<T, IFlagsmithTrait> and the runtime identify() in flagsmith-core.ts already handles it via isTraitEvaluationContext().

Fix

Type-only change in types.d.ts: identify() traits now use IFlagsmithTrait, matching setTraits()/setTrait(). This widens the accepted type — no existing caller breaks.

Tests

Added a case to test/types.test.ts that calls both setTraits() and identify() with the same trait object containing a transient TraitEvaluationContext, plus a @ts-expect-error for an undeclared trait key so the generic T is still enforced.

Validation (Node 22.14):

• npx tsc before the fix: test/types.test.ts(103,62): error TS2322: Type '{ value: string; transient: true; }' is not assignable to type 'string | number | boolean | null'
• npx tsc after the fix: exit 0
• npm test (jest --env=jsdom): 19 suites, 126 tests passed

Closes #383

[Zaimwa9]

Great! Thanks for the contribution