Add LogVole chosen-input VOLE

[ladnir]

Summary

• Add ENABLE_LOGVOLE for the semi-honest Ring-LWE LogVole chosen-input VOLE protocol.
• Integrate LogVole into libOTe with stock Microsoft SEAL 4.1.1 via SEAL::seal.
• Add public LogVoleSender / LogVoleReceiver APIs, coproto networking paths, frontend examples, docs, and README citation.
• Add a curated 30-test LogVole native test suite covering core math, encoding, key derivation, shrink/expand, CI-VOLE state, and coproto paths.

Tests

• cmake --build out/build/linux --target frontend_libOTe -- -j4
• ctest --test-dir out/build/linux -R LogVoleNativeTests --output-on-failure
• ./out/build/linux/frontend/frontend_libOTe -logvole -n 8

Notes

• LogVole is gated behind ENABLE_LOGVOLE.
• ENABLE_LOGVOLE=ON requires stock Microsoft SEAL 4.1.1.
• The implementation is ported from the cleaned LogVole code path and avoids importing the old networking layer.