Remove to_bytes / from_bytes from non-top-level Python wrappers

[termoshtt]

Summary

Drops bytes serialization (to_bytes / from_bytes) from component-level Python wrappers. Top-level container types and cross-evaluate DTOs keep bytes serialization unchanged.

This is a Python SDK breaking change, split out from #843 so the larger metadata-storage refactor can land separately. The Rust SDK is unchanged in this PR — only the PyO3 binding surface narrows.

Affected types

Removed to_bytes / from_bytes:

• Function, Linear, Quadratic, Polynomial
• Parameter
• NamedFunction, EvaluatedNamedFunction, SampledNamedFunction
• DecisionVariable, EvaluatedDecisionVariable, SampledDecisionVariable

Kept (top-level + cross-evaluate DTOs):

• Instance, ParametricInstance, Solution, SampleSet
• State, Samples, Parameters

Rationale

These methods originally existed because the pre-v3 Python SDK had its own protobuf-based wrapper layer, so every value crossing the Python ↔ Rust boundary had to be serialized — to_bytes / from_bytes was the bridge. With v3's switch to direct PyO3 re-exports the boundary is gone, and element-level bytes round-trips no longer serve a purpose. The upcoming metadata-storage redesign (#843 lineage) would only inflate the maintenance cost of keeping them, so they're retired now.

Test plan

• task python:stubgen regenerated stubs and docs/api/api_reference.json
• task python:test passes (ommx core + highs / pyscipopt / python-mip / openjij adapters)
• task format clean

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR narrows the Python (PyO3) binding surface by removing to_bytes / from_bytes from non-top-level “component” wrapper types, keeping bytes serialization only on top-level container types and cross-evaluate DTOs to avoid metadata-lossy round-trips.

Changes:

• Removed to_bytes / from_bytes methods from component-level wrappers (e.g., DecisionVariable, Function, Linear, NamedFunction, evaluated/sampled variants).
• Regenerated Python stubs (__init__.pyi) and API reference JSON to reflect the updated public surface.
• Removed Python tests that exercised now-deleted component-level bytes round-trips.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
python/ommx/src/decision_variable.rs	Removes bytes serialization APIs from DecisionVariable wrapper.
python/ommx/src/evaluated_decision_variable.rs	Removes bytes serialization APIs from EvaluatedDecisionVariable wrapper.
python/ommx/src/sampled_decision_variable.rs	Removes bytes serialization APIs from SampledDecisionVariable wrapper.
python/ommx/src/function.rs	Removes bytes serialization APIs from Function wrapper.
python/ommx/src/linear.rs	Removes bytes serialization APIs from Linear wrapper.
python/ommx/src/quadratic.rs	Removes bytes serialization APIs from Quadratic wrapper.
python/ommx/src/polynomial.rs	Removes bytes serialization APIs from Polynomial wrapper.
python/ommx/src/parameter.rs	Removes bytes serialization APIs from Parameter wrapper.
python/ommx/src/named_function.rs	Removes bytes serialization APIs from NamedFunction wrapper.
python/ommx/src/evaluated_named_function.rs	Removes bytes serialization APIs from EvaluatedNamedFunction wrapper.
python/ommx/src/sampled_named_function.rs	Removes bytes serialization APIs from SampledNamedFunction wrapper.
python/ommx/ommx/_ommx_rust/init.pyi	Updates generated stubs to remove the deleted methods from affected classes.
python/ommx-tests/tests/test_named_function.py	Removes NamedFunction bytes round-trip test that no longer applies.
docs/api/api_reference.json	Updates generated API reference to remove the deleted methods from affected classes.