Add TypeScript runtimeuse client package and documentation

[jackcbrown89]

Summary

Adds a TypeScript client package (runtimeuse-client) equivalent to the existing Python runtimeuse-client package, along with full documentation updates.

TypeScript Client Package

Package Structure

packages/runtimeuse-client-ts/
├── src/
│   ├── index.ts                          # Public API exports
│   ├── client.ts                         # RuntimeUseClient class
│   ├── types.ts                          # Protocol types and QueryOptions
│   ├── exceptions.ts                     # AgentRuntimeError, CancelledException
│   ├── send-queue.ts                     # Async message queue
│   ├── transports/
│   │   ├── transport.ts                  # Transport type definition
│   │   ├── websocket-transport.ts        # WebSocket transport
│   │   └── index.ts
│   ├── client.test.ts                    # Client unit tests
│   ├── exceptions.test.ts               # Exception tests
│   └── send-queue.test.ts               # SendQueue tests
├── package.json
├── tsconfig.json
└── vitest.config.ts

API Surface

Symbol	Type	Description
RuntimeUseClient	Class	Main client with query() and abort()
Transport	Type	Transport interface for custom implementations
WebSocketTransport	Class	WebSocket transport
AgentRuntimeError	Error	Runtime error with .error and .metadata
CancelledException	Error	Cancellation signal
SendQueue	Class	Async queue for outbound messages
QueryOptions	Interface	Query configuration
QueryResult	Interface	Result with .data and .metadata
TextResult	Interface	Text result variant
StructuredOutputResult	Interface	Structured output result variant
+ all protocol message types	Interfaces	Wire format types

Tests

33 unit tests covering: result messages, assistant message dispatch, error handling, artifact upload handshake, cancellation, timeout, unknown messages, message sequencing, invocation construction, and validation.

Documentation Updates

• New page: typescript-client.mdx — Full API reference matching python-client.mdx with sections for basic query, structured JSON, downloadables, artifact uploads, streaming, cancellation, timeout, secret redaction, and error handling.
• meta.json — Added TypeScript Client to sidebar navigation (between Python Client and Agent Runtime).
• index.mdx — Updated description to mention TypeScript alongside Python.
• quickstart.mdx — Added Python/TypeScript tabs for the install and connect steps so users can choose their preferred language.