ci: load ecosystem for deadcode analysis

[Patel230]

Summary

• materialize every pinned ecosystem repository before deadcode analysis
• capture the full inventory before truncating display output
• allow loader/import failures to fail the job instead of being masked by the head pipeline

Verification

• actionlint passes for .github/workflows/ci.yml
• git diff --check passes
• full pinned graph loads locally with 3,936 informational deadcode entries and no loader/import errors

This keeps the existing dead-code inventory informational while making an incomplete analysis a real failure.