fix: export FlagSource enum as runtime value

Export FlagSource enum from all entry points to make it usable as both a type and runtime value in consumer code.

Previously, FlagSource was only exported as a type declaration, which prevented users from comparing against enum values like FlagSource.NONE in their code. Users had to use workarounds with string literals and type assertions.

Changes:
- Export enum from flagsmith-core.ts
- Re-export from types.d.ts referencing the real enum
- Add FlagSource export to all entry points:
  - index.ts (web browser)
  - isomorphic.ts (SSR/universal)
  - index.react-native.ts (React Native)
  - next-middleware.ts (Next.js edge)

Users can now use:
  import { FlagSource } from 'flagsmith';
  if (loadingState.source === FlagSource.NONE) { ... }

Author: talissoncosta

flagsmith-core.ts

@@ -27,7 +27,7 @@ import { isTraitEvaluationContext, toEvaluationContext, toTraitEvaluationContext
 import { ensureTrailingSlash } from './utils/ensureTrailingSlash';
 import { SDK_VERSION } from './utils/version';
 
-enum FlagSource {
+export enum FlagSource {
     "NONE" = "NONE",
     "DEFAULT_FLAGS" = "DEFAULT_FLAGS",
     "CACHE" = "CACHE",

index.react-native.ts

@@ -14,3 +14,4 @@ export const createFlagsmithInstance = ()=>{
         eventSource: _EventSource
     })
 }
+export { FlagSource } from './flagsmith-core';

index.ts

@@ -19,3 +19,4 @@ export default flagsmith;
 export const createFlagsmithInstance = ():IFlagsmith=>{
     return core({ AsyncStorage, fetch:_fetch, eventSource:_EventSource})
 }
+export { FlagSource } from './flagsmith-core';

isomorphic.ts

@@ -24,3 +24,4 @@ export const createFlagsmithInstance = (): IFlagsmith => {
         eventSource: typeof window !=='undefined'?eventSource : null
     })
 }
+export { FlagSource } from './flagsmith-core';

next-middleware.ts

@@ -5,3 +5,4 @@ export default flagsmith;
 export const createFlagsmithInstance = ():IFlagsmith=>{
     return core({})
 }
+export { FlagSource } from './flagsmith-core';

types.d.ts

@@ -84,12 +84,7 @@ export type ISentryClient = {
 } | undefined;
 
 
-export declare enum FlagSource {
-    "NONE" = "NONE",
-    "DEFAULT_FLAGS" = "DEFAULT_FLAGS",
-    "CACHE" = "CACHE",
-    "SERVER" = "SERVER",
-}
+export { FlagSource } from './flagsmith-core';
 
 export declare type LoadingState = {
     error: Error | null, // Current error, resets on next attempt to fetch flags