Add Redmine MCP to OpenCode

[CollieIsCute]

Summary

• add RedmineMCP as an OpenCode local MCP server
• point to the existing local redmine-mcp binary from Sunalamye/RedmineMCP
• pass the Redmine URL as a command argument

Security

• no Redmine token or API key is committed
• credentials remain local to RedmineMCP login/profile handling or runtime environment

Verification

• chezmoi execute-template < home/dot_config/opencode/opencode.json.tmpl | jq . > /dev/null
• checked staged diff for secret-looking keys before commit

[CollieIsCute]

Closing because Redmine MCP must be enabled manually and must not commit company-specific Redmine configuration.