fix: fix-drift.ts path truncation and missing label

[jpr5]

Summary

• Change exec() .trim() to .trimEnd() — preserves leading whitespace in git porcelain output that encodes index/worktree status
• Create drift label on repo so gh issue create --label drift succeeds

Test plan

• Verified porcelain parsing logic handles M src/file.ts correctly with trimEnd

[pkg-pr-new]

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npm i https://pkg.pr.new/@copilotkit/aimock@186

commit: cacf3cb