feat: TypeScript memory client

[0xpolarzero]

Warning

This PR is part of a stacked PR chain.

Upstream merge PRs:
wevm/incur#144 ->
wevm/incur#145 ->
wevm/incur#143 ->
wevm/incur#147

Correctly based review stack in this fork:
#3 ->
#4 ->
#5 ->
#2

Overview

Adds an in-memory TypeScript client that calls incur commands directly from a Cli instance without running an HTTP server.

API

import { create, createMemoryClient } from 'incur'
import { z } from 'zod'

const cli = create('project')
  .command('deploy', {
    args: z.object({ id: z.string() }),
    options: z.object({ dryRun: z.boolean().default(false) }),
    output: z.object({ id: z.string(), url: z.string() }),
    run: ({ args, options }) => ({
      id: args.id,
      url: options.dryRun ? 'preview://deploy' : 'https://example.com/deploy',
    }),
  })
  .command('logs', {
    args: z.object({ id: z.string() }),
    output: z.object({ line: z.string() }),
    async *run() {
      yield { line: 'deploy started' }
    },
  })

const client = createMemoryClient(cli)

const result = await client('project deploy')({
  args: { id: 'p1' },
  options: { dryRun: true },
})
//    ^? { id: string; url: string }

const stream = await client('project logs')({
  args: { id: 'p1' },
})
//    ^? AsyncIterable<{ line: string }>

Maintainer Notes

• createMemoryClient(cli, { env }) accepts an optional env source used for CLI-level and command-level env parsing.
• Cli value stream inference is structural for handlers returning AsyncGenerator; runtime/typegen streaming detection still relies on actual async *run handlers.
• This PR does not add a changeset because it is part of the still-unreleased TypeScript client stack.

Changes

• Add createMemoryClient(cli) with the same typed call shape as createClient.
• Share structured RPC execution between HTTP and in-memory clients.
• Preserve validation, middleware, errors, CTAs, root commands, aliases/root aliases, env parsing, and streaming cleanup across both paths.
• Keep raw fetch gateways unsupported by structured RPC.
• Extend Cli command maps with output metadata and structural stream metadata for local client inference.

Tests

• Adds memory client runtime coverage for data, validation, errors, middleware, root commands, aliases, env parsing, streams, and cancellation.
• Adds type tests for createMemoryClient(cli) inference, mounted CLIs, outputs, and streaming calls.
• Adds RPC coverage for root command execution and stream cancellation.