add runtime arg validation, remove Pipeline abstraction

Add $validate for schema-derived arg validation with Levenshtein
did-you-mean suggestions. Remove Pipeline/pipe API in favor of
$spawn's native async iterator — just use for-await loops.

Author: aidenybai

packages/cli-to-js/src/build-api.ts

@@ -8,7 +8,6 @@ import {
 } from "./exec.js";
 import { parseSubcommandHelp, enrichSubcommands } from "./parse-subcommands.js";
 import { validateOptions, type ValidationError } from "./validate.js";
-import { createPipelineProxy } from "./pipe.js";
 import type { CliApi } from "./cli-api.js";
 
 const RESERVED_PROPERTIES = new Set([
@@ -156,7 +155,6 @@ export const buildApi = <
     get(target, property) {
       if (property === "$schema") return schema;
       if (property === "$validate") return handleValidate;
-      if (property === "$pipe") return createPipelineProxy(binaryName, defaultConfig);
       if (property === "$spawn") return buildSpawnProxy();
       if (property === "$parse") return handleParse;
       if (typeof property === "symbol") return Reflect.get(target, property);

packages/cli-to-js/src/cli-api.ts

@@ -1,7 +1,6 @@
 import type { CommandResult, RunConfig, CommandProcess } from "./exec.js";
 import type { CliSchema, ParsedCommand } from "./parse-help-text.js";
 import type { ValidationError } from "./validate.js";
-import type { Pipeline } from "./pipe.js";
 
 interface SubcommandFn<TOptions = Record<string, unknown>> {
   (
@@ -38,8 +37,6 @@ interface CliApiBase {
     (options?: Record<string, unknown>, config?: RunConfig): CommandProcess;
     (subcommand: string, options?: Record<string, unknown>, config?: RunConfig): CommandProcess;
   };
-  $pipe: Pipeline &
-    Record<string, (options?: Record<string, unknown>, config?: RunConfig) => Pipeline>;
 }
 
 type CliApi<

packages/cli-to-js/src/index.ts

@@ -38,9 +38,6 @@ export { loadSchema } from "./load-schema.js";
 export { parseSubcommandHelp, enrichSubcommands } from "./parse-subcommands.js";
 export { generate, generateTypes } from "./generate.js";
 export { validateOptions } from "./validate.js";
-export { Pipeline, createCommandStep, createPipelineProxy } from "./pipe.js";
-export { map, filter, take } from "./utils/async-iterable.js";
-export type { AsyncTransform } from "./utils/async-iterable.js";
 export type { ValidationError } from "./validate.js";
 export type { CliApi, CliApiBase, SubcommandFn, SpawnFn } from "./cli-api.js";
 export type {