Refactor to use const refs and std::move for efficiency;

[SunnyWar]

• Pass expensive-to-copy parameters as const references where possible
• Apply std::move to transfer ownership in constructors and factory registrations
• Update lambdas to take const refs for non-modified parameters
• Include in affected files to support std::move
  ref: https://releases.llvm.org/20.1.0/tools/clang/tools/extra/docs/clang-tidy/checks/performance/unnecessary-value-param.html

[mooskagh]

Note that most of our usages of std::string would actually be better to replace with std::string_view. That's something that I wanted to do but didn't have time.

I'll take a closer look next week, unless somebody else beats me to it.

[Copilot]

Pull Request Overview

This PR refactors the codebase to improve performance by using const references and std::move for expensive-to-copy parameters, following clang-tidy performance recommendations.

• Pass string parameters as const references to avoid unnecessary copies
• Apply std::move for ownership transfer in constructors and factory registrations
• Add <utility> includes where std::move is used

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/trainingdata/writer.cc	Add utility include and use std::move in constructor
src/trainingdata/reader.cc	Add utility include and use std::move in constructor
src/tools/backendbench.cc	Convert function parameters to const references
src/search/classic/search.cc	Add utility include, update lambda and function parameters
src/search/classic/params.cc	Convert function parameters to const references
src/neural/wrapper.cc	Add utility include, update function parameters and constructor
src/neural/onnx/converter.cc	Convert function parameters to const references
src/neural/onnx/adapters.cc	Convert template function parameter to const reference
src/neural/factory.cc	Add utility include and use std::move in factory registration
src/neural/backends/network_mux.cc	Convert shared_ptr parameter to const reference

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