feat(integrations): add free Parallel Search MCP

[georgeatparallel]

• A human has tested these changes.

Why

Parallel Search MCP works without an API key, but users currently have to add its URL manually. This makes it available in the shared integration catalog.

Summary

• Add an opt-in, no-auth Streamable HTTP entry for Parallel Search MCP and regenerate the JS index.
• Update the public-server allowlist and add an opt-in live test for search, page fetching, source links, and invalid arguments.
• Leave existing integrations, search defaults, and saved settings alone.

Issue Number

No matching issue yet. Keeping this in draft pending a scoped issue that meets the repository's readiness requirements.

How to Test

uv sync --group test
npm run build:integrations
uv run pytest -q
RUN_PARALLEL_MCP_LIVE=1 uv run pytest -q tests/test_live_integration_smoke.py -k parallel

786 tests passed, 15 skipped. The live test passed through the OpenHands SDK without a Parallel credential, including both tools and their source-bearing responses.

With this package linked into Agent Canvas, 52 focused component/helper tests passed, including credential-free installation and preservation of sibling servers. The full hosted UI was not exercised.

Video/Screenshots

Not applicable to this catalog and test change.

Notes

Anonymous Search MCP is free for light use and rate-limited. This does not change model or hosting costs. Availability in released clients follows the next catalog release and consumer update.

[all-hands-bot]

👋 This PR needs a couple of things fixed before OpenHands can review it:

• the PR description's HUMAN: section needs at least 20 characters describing what you tested, not just the template placeholder

Push an update once this is addressed and this check re-runs automatically.

This is an automated check - no AI was used to generate this comment.