Add session connector: GitHub Copilot

[Railly]

Context

GitHub Copilot stores skills in ~/.copilot/skills/. Need to investigate session data format.

What's Needed

1. Investigate Copilot's session storage format (VS Code extension data)
2. Determine if skill invocations are trackable
3. If trackable: build connector at packages/cli/src/scanner/connectors/copilot.ts

References

• Skills path: ~/.copilot/skills/