Add Intercom integration

[pagkt2]

Summary

Adds an intercom integration that proxies Intercom's official remote MCP server via the existing remotemcp package. Same pattern as linear.New("https://mcp.linear.app") (and the pganalyze migration in #156): a thin wrapper so tools are auto-prefixed intercom_*, and configure / tools / execute / healthy delegate to the upstream server.

Intercom's MCP currently exposes 13 tools — universal (search, fetch), conversations (search_conversations, get_conversation), contacts (search_contacts, get_contact), companies (list_companies, get_company), and articles (list_articles, search_articles, get_article, create_article, update_article). They'll surface automatically through search / execute and follow upstream as Intercom expands tool coverage.

Changes

• integrations/intercom/intercom.go — ~50-line wrapper around remotemcp.New("intercom", "https://mcp.intercom.com"). Optional URL override for tests.
• integrations/intercom/intercom_test.go — constructor, name, configure delegation (incl. missing/empty token), healthy without config, execute against unreachable host.
• cmd/server/main.go — register intercom.New() in the integration list (placed next to linear.New since both are remote MCP proxies).
• config/config.go — defaultConfig entry with access_token credential, INTERCOM_ACCESS_TOKEN env mapping.
• README.md — env-vars table entry.

Auth

Workspace Access Token from Intercom's developer hub — passed to remotemcp as creds["access_token"], which wires it into Authorization: Bearer <token> via the existing bearerTransport. Required scopes per Intercom's MCP docs: read users/companies, read conversations, and read/write articles if the article tools are used. OAuth not wired (Intercom MCP supports both PAT and OAuth; PAT is sufficient for first-party data access — happy to follow up with an OAuth flow if useful).

Test plan

• CI green (build, vet, test-race, lint, security)
• Local smoke: INTERCOM_ACCESS_TOKEN=... ./switchboard then call search with intercom filter — confirm 13 tools surface
• execute intercom_search_articles with a query and verify a response

Made with Cursor

[pagkt2]

Local smoke test ✅

Tested the integration locally against a real Intercom workspace. Results:

• search with integration: intercom returns all 13 tools correctly prefixed as intercom_*
• execute intercom_get_conversation with a real conversation ID returned the full thread, message history, internal notes, tags, and statistics — no empty {} or compaction issues
• Auth via INTERCOM_ACCESS_TOKEN env var auto-enables the integration without touching config.json

The remote MCP proxy handshake (initialize + tools/list against https://mcp.intercom.com) completes successfully and tools surface through search/execute as expected.