docs: add hosted keyless search MCP example

[georgeatparallel]

Issue Link (REQUIRED)

Fixes #687

Summary

Changes

Adds a hosted web-search example to the existing MCP Tool Provider guide in Python and TypeScript. Users can connect to Parallel's free, rate-limited Search MCP without a Parallel account or API key, discover web_search and web_fetch, and clean up the connection.

Parallel's anonymous search uses Fast mode. DeepSearchQA results and time per task provide independent evaluation context; they don't measure this Agent Squad example. I work at Parallel.

User experience

The existing remote examples use a local server or a placeholder URL. This adds a hosted endpoint readers can try using the same provider and transport. It explains data sent to Parallel, the project-wide User-Agent used for aggregate usage measurement, and the separate model-provider setup an agent still needs. Existing routing, defaults, dependencies, and examples are unchanged.

Validation

The docs build passed. Both snippets were exercised through the repository's native MCP provider: discovery exposed both tools, search returned results with URLs and excerpts, fetch returned documentation excerpts, and disconnect completed. Captured Search and Fetch requests carried User-Agent: agent-squad without Authorization. Downstream analytics attribution hasn't been verified.

Checklist

• I have performed a self-review of this change
• Changes have been tested
• Changes are documented
• I have linked this PR to an existing issue (required)

Is this a breaking change?

No.

Acknowledgment

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.