chore(core): drop unused readExt helper and its public export

Author: felixweinberger

packages/core/src/exports/public/index.ts

@@ -49,7 +49,7 @@ export type {
     RequestOptions,
     ServerContext
 } from '../../shared/protocol.js';
-export { DEFAULT_REQUEST_TIMEOUT_MSEC, readExt } from '../../shared/protocol.js';
+export { DEFAULT_REQUEST_TIMEOUT_MSEC } from '../../shared/protocol.js';
 
 // Task manager types (NOT TaskManager class itself — internal)
 export type { RequestTaskStore, TaskContext, TaskManagerOptions, TaskRequestOptions } from '../../shared/taskManager.js';

packages/core/src/shared/context.ts

@@ -196,15 +196,6 @@ export type BaseContext = {
     ext?: Record<string, unknown>;
 };
 
-/**
- * Typed reader for an extension key on {@linkcode BaseContext.ext}. Extensions export
- * a thin wrapper around this (e.g. `taskContext(ctx)`) so handlers get a typed value
- * without casting at the call site.
- */
-export function readExt<T>(ctx: BaseContext, key: string): T | undefined {
-    return ctx.ext?.[key] as T | undefined;
-}
-
 /**
  * Context provided to server-side request handlers, extending {@linkcode BaseContext} with server-specific fields.
  */