Merge branch 'main' into agent/fix-go-selector-call-targets

Keep both test blocks at the shared anchor in tests/test_multilang.py:
the generic-receiver regression from #833 and the receiver-call
resolution tests from this branch.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012fHfGDiZedoxjpKzanHri3