Added

• abstraction_leak_surgery detector — files that co-change in git history and share a third-party type in their function signatures. Upgrade of the classic shotgun_surgery: instead of "these files always change together" (agnostic of why), this pinpoints "these files always change together because they all depend on the same external type" — the shared external type is the concrete abstraction leak driving the co-change cascade. Severity Hint.
  • Inputs: git co-change counts (git log --name-only -N, threshold ≥ 5 commits in last 100) × per-file TypeOrigin::External sets derived from parameter / return types. Workspace-sibling crates auto-whitelisted (same mechanism cross_boundary_chain / leaky_public_signature use), so cha_core-internal dependencies between cha-parser / cha-cli don't fire.
  • Cha self-baseline: 10 genuine findings, all pointing at the 5 language parsers sharing tree_sitter::Node — exactly the abstraction leak the detector is designed to find (tree-sitter upgrades ripple across every parser file). lvgl src/: 0 (C project, no External origins).