docs: add Pairoa MCP server

[wzczv]

Summary\n\nAdd Pairoa to the third-party MCP server list under collaboration/communication.\n\nPairoa is a privacy-first remote MCP for matching needs, offers, and opportunities. It exposes a hosted Streamable HTTP endpoint at:\n\n- https://mcp.pairoa.com\n\nOfficial public integration docs:\n\n- https://github.com/pairoa/docs\n\n## Verification\n\nThe endpoint is publicly reachable and supports MCP OAuth discovery. The public docs include install instructions and tool details.

[wzczv]

Hi maintainers, adding a quick verification note for this MCP server submission:

• Official MCP Registry ID: com.pairoa/pairoa
• Canonical public repo: https://github.com/pairoa/docs
• Remote MCP endpoint: https://mcp.pairoa.com
• Transport: Streamable HTTP
• Auth: OAuth / Bearer challenge with standard MCP protected-resource and authorization-server metadata

Read-only production smoke check on 2026-07-08 09:35 CST:

MCP_SMOKE_URL=https://mcp.pairoa.com npx tsx scripts/mcp-smoke.test.ts
Passed: 10
Failed: 0
Warn: 1
Warn reason: deep OAuth handshake intentionally skipped in read-only smoke mode.

Pairoa is a remote MCP server for privacy-first matching of needs, offers, and opportunities. It does not require local file access or local secrets.