D51 — MCP server name fixed to "cartographer"; auto-trust hint with the exact command

Decision. The name under which the server is registered in the providers' MCP configs is no longer configurable via flag/form: it is always cartographer (escape hatch: server_name in .cartographer.yaml). Every "needs approval" message now prints the exact command to run (cartographer sync --auto-trust) via autoTrustCommand, instead of the vague "use --auto-trust". Rationale. The name was a knob with no real use cases that lengthened the form and risked duplicate MCP entries on every rename.

(Superseded state: --global removed from autoTrustCommand/everywhere → D52.)