feat/copilot cli mcp support

[dyoshikawa-claw]

• feat(mcp): add GitHub Copilot CLI MCP support (Generate .copilot/mcp-config.json for GitHub Copilot CLI #1319)
• fix(copilot-cli-mcp): address Copilot review feedback
• fix: rename copilot-cli to copilotcli
• fix: rename copilot-cli files to copilotcli
• fix: import order and unused import
• fix: add type keyword to import
• fix: fix CI failures and rename copilot-cli to copilotcli
• fix: fix eslint unused var and reformat files
• test: fix EACCES by using dynamic test directory instead of absolute paths
• chore: add copilotcli to cspell dictionary
• feat(opencode): honor agentsmd subproject path

[dyoshikawa-claw]

Self-review (OpenCode): the change looks sound overall. One caveat: when is set, now emits in the subproject directory rather than a file under . That matches the current shared helper behavior and Codex CLI parity, but it may be surprising on round-trip. If intentional, it would be worth calling out in docs/tests; otherwise we may want to preserve the non-root filename/path semantics for OpenCode specifically.