fix: classify constructor type parameters

[rogerchappel]

Summary

• Add regression coverage for weak types in constructor signature parameters and returns.
• Classify constructor signatures with the same combined parameter/return logic as function signatures.
• Document constructor signature coverage and any precedence.

Verification

• Tests or checks run: npm run release:check; git diff --check
• Manual review completed: reviewed all four changed files and three commits

Regression evidence: the new focused cases failed in four places before the implementation change and pass afterward. The full suite passes with 146 tests.

Commit-by-commit changes

• test: cover constructor type annotations — covers any, unknown, explicit annotations, and precedence across constructor parameters and returns.
• fix: classify constructor type parameters — combines every constructor parameter annotation with its return type.
• docs: document constructor signature coverage — updates README behavior and the changelog.

Risk Level

• Low
• Medium
• High

Notes: The implementation reuses the existing, tested function-signature classifier and changes no public API.

Rollback Plan

• Revert the three commits in reverse order.

Human Decision Needed

• None
• Maintainer review
• Product/design decision
• Security/privacy review
• Other:

[rogerchappel]

Automated merge note

Triage class: auto-merge

Summary: Classifies weak types in constructor signature parameters as well as returns, with focused regression coverage and documentation (4 files, +28/-8).

Checks run: GitHub CI test (20.19.0), test (22), and test (24) — all COMPLETED/SUCCESS; git diff --check origin/main...HEAD; final diff, mergeability, branch protection (one approval only; no required status checks), and Roger Chappel author/committer identities re-verified.

Rebased/CI-repaired: No.

Verified head SHA: 0b018708db3c0b5ad2c0bf9e6b669a4ecbc9d550.