fix: detect installed ALSA runtime library

[filipeforattini]

Summary

• detect libasound2t64 through the multiarch libasound.so.2 it installs
• support both x64 and arm64 Ubuntu library paths
• add a regression test for the doctor/install-state false negative

Validation

• git diff --check
• full test and typecheck suite delegated to CI for this low-resource workstation

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