[Feature]: Copilot CLI (copilotcli) lacks Commands, Subagents, Skills, and Hooks support

[flanny7]

Hello, I always appreciate rulesync.

Problem

There is a significant feature gap between copilot and copilotcli. The following features are implemented for copilot but not for copilotcli:

Feature	copilot	copilotcli
Rules	✅	✅
MCP	✅	✅
Commands	✅	❌
Subagents	✅	❌
Skills	✅	❌
Hooks	✅	❌
Ignore	❌	❌
Permissions	❌	❌

Evidence

The src/features/commands/, src/features/subagents/, src/features/skills/, and src/features/hooks/ directories contain copilot-*.ts files but no corresponding copilotcli-*.ts files.

Proposed Solution

If GitHub Copilot CLI supports equivalent configuration formats for these features, implement the corresponding copilotcli-*.ts processors and register them in each feature's processor.

If Copilot CLI does not support these features natively, document the limitation clearly in the supported features matrix.

Your consideration would be appreciated.