fix: warmup timeout

[EdouardBougon]

Description

New Features

• Configurable Request Timeouts:

  • Default value is -1 (no timeout) to accommodate user interactions
  • Value of -1 explicitly disables timeout

• Warmup Timeout: Added warmupTimeout parameter for the initial connection handshake

  • Default value is 200ms (defined in DEFAULT_WARMUP_TIMEOUT)
  • Used specifically for the first wallet_getSession request after connection
  • Helps handle cases where the extension needs time to initialize

Why These Changes?

1. User Interaction Support: Most Multichain API operations require user confirmation (e.g., signing transactions). The default -1 timeout prevents premature request cancellation.

2. Initialization Reliability: The warmupTimeout addresses a specific issue where the first request after connection may need extra time to complete (see MetaMask Mobile issue #16550).

3. Flexibility: Developers can now configure timeouts based on their specific needs while maintaining sensible defaults.

Example Usage

// Default behavior (no timeout for requests, 200ms warmup)
const transport = getDefaultTransport();

// Custom timeouts
const transport = getDefaultTransport({
  defaultTimeout: 30000,  // 30 seconds for all requests
  warmupTimeout: 500      // 500ms for initialization
});

// Disable timeouts completely
const transport = getDefaultTransport({
  defaultTimeout: -1,
  warmupTimeout: -1
});

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Adds configurable warmupTimeout for the initial request and sets default request timeout to -1 across transports and client, with docs and tests updated.
> 
> - **Transport**:
>   - Add `warmupTimeout` to `Transport` interface and expose in `windowPostMessage` and `externallyConnectable` transports (default `200ms`, configurable, supports `-1`).
>   - Set `DEFAULT_REQUEST_TIMEOUT` to `-1` (no timeout by default); plumb `defaultTimeout`/`warmupTimeout` through `getDefaultTransport` and transport factories.
> - **Client**:
>   - Use `transport.warmupTimeout ?? 1_000` for initial `wallet_getSession` during initialization.
> - **Helpers**:
>   - `withTimeout` supports `-1` to disable timeouts.
> - **Docs**:
>   - README adds timeout configuration section with examples and comparison table.
> - **Tests**:
>   - Update/add tests for warmup timeout exposure/defaults, initial call timeout option, request timeout behavior, and `withTimeout(-1)`.
> 
> <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit a2e5e9a541dfbad048b04672dbd8e00e8372a4f0. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->