fix(git): rewrite -C with quoted paths

[fengjikui]

Summary

• extend the git hook/discover rewrite pattern so git -C "path with spaces" <subcommand> routes through rtk git
• keep the original quoted -C path in the rewritten command
• add regression coverage for classification, rewrite, and global-option stripping

Context

Issue #2303 reports missed git -C <path> rewrites. Current develop already handles unquoted paths such as git -C /tmp status, but the same rewrite still missed valid quoted paths with spaces because the matcher only accepted \S+ values.

Before this change, the Claude hook produced no rewrite for:

git -C "/tmp/foo bar" status

After this change it rewrites to:

rtk git -C "/tmp/foo bar" status

Validation

• cargo fmt --check
• cargo test discover::registry::tests
• cargo test
• cargo clippy --all-targets -- -D warnings
• git diff --check
• manual hook check with git -C "/tmp/foo bar" status

AI Assistance

This PR was prepared with OpenAI Codex assistance. I reviewed the diff and ran the validation above before submitting.