fix: allow cross-cwd managed worktree patches

[andrei-hasna]

Summary

• recognize absolute file-tool targets inside a different verified linked managed worktree
• fail closed for malformed/standalone repos, Git metadata, roots, symlink/hardlink escapes, and forged worktree provenance
• cache managed-root discovery across multi-file patches

Verification

• bun test src/hooks/codewith-native.test.ts — 47 passed
• bun test — 876 passed
• bun run typecheck
• git diff --check
• staged gitleaks scan — no leaks
• fresh independent adversarial review — GO, no P0/P1

No global hook install, package publication, deployment, or fleet rollout is included.