docs: add optional Parallel Search MCP setup

[georgeatparallel]

Summary

Document an optional Parallel Search MCP setup using Cognipeer Console's existing remote MCP source flow. The setup is explicitly opt-in, uses Parallel's no-key upstream endpoint, and continues to require Cognipeer gateway authorization for gateway requests.

Changes

• Add dashboard settings for a separate parallel-search remote MCP server using Streamable HTTP with no upstream authentication.
• Add an authenticated gateway web_search example with both objective and search_queries.
• Preserve existing providers, configuration, security controls, and defaults.
• Disclose that user-provided search objectives, search queries, and requested URLs are sent to Parallel when its tools are explicitly used.

Validation

• git diff --check

Release Notes

• Docs updated when behavior changed
• Security-sensitive changes reviewed
• License or policy files updated if repo-facing behavior changed

Disclosure: I work at Parallel.ai, which operates this MCP endpoint.