MCP: expose record merge as a tool (mergeCompanies/mergePeople already exist in GraphQL)

Summary There is no merge tool anywhere in the MCP surface, so an agent that creates a duplicate cannot repair it. The capability already exists — mergeCompanies and mergePeople are GraphQL mutations, and merge is available in the UI — it is simply not exposed as a tool. The bundled crm-hygiene skill acknowledges the gap and routes around it: > You cannot merge records. There is no merge tool; merging happens in the UI, where the user selects the records and uses the Merge action. Report each duplicate pair with both records referenced and leave the merge to them. So the agent-facing story for the one operation that fixes duplicates is "ask a human to go and do it". Why this matters more than a typical missing tool Duplicate prevention is only partial, which makes repair load-bearing: • The database enforces a unique constraint on the company domain, so a second record on the same domain is blocked. • Name duplicates are not blocked. On a stock workspac…