[adilalperenciftci]

Summary

I traced the effect-tag gap to function-clause lookup: the checker scanned only the annotated clause and followed only the first clause of a transitive callee. A later pattern clause could therefore reach a forbidden capability while @pure, @no_fs, @no_net, or @no_os still passed.

This change:

1. checks every clause sharing the tagged function name;
2. follows every clause of a resolved callee during transitive effect analysis;
3. adds direct and transitive multi-clause rejection cases.

Verification

• BEFORE: both new multi-clause cases compiled.
• AFTER: both are rejected with the expected os effect diagnostic.
• sh tests/integration/effect_tags/test_effect_tags.sh
• sh tests/integration/aetherc_emit_effects/test_aetherc_emit_effects.sh
• make check-changelog
• make check-tests
• make test (634 passed)

Signed-off-by: Adil Alperen Çiftci adilalperenciftci@users.noreply.github.com

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[paul-hammant]

Thanks, reviewed and folded into the batch #3456 with your authorship kept on the commit. This PR will be closed when #3456 merges.

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[paul-hammant]

Merged as part of #3456 (merge 9364d6b), with your authorship on the commit. Thank you, @adilalperenciftci: this was a real fix, carefully tested, and it's appreciated.

🤖 Generated with Claude Code