bugfix(plugins): Sanitize hash and serde implementation. - #10117

Summary

Fix variable name shadowing in #[derive(Hash)] and #[derive(Serde)] code generation when a struct field is named value (for Hash) or serialized (for Serde).

The generated update_state implementation for Hash used to bind each member into a local variable named after the field itself (e.g., let value = ...). If a field was named value, this shadowed the update_state function parameter value, causing incorrect code generation. Similarly, the Serde deserialize implementation bound members into locals named after the field, which could shadow the ref serialized parameter if a field was named serialized.

The fix prefixes all generated intermediate locals with __hash_derive_member_ (for Hash) and __serde_member_ (for Serde) to avoid any collision with parameter names or other identifiers.

Type of change

Please check one:

• Bug fix (fixes incorrect behavior)
• New feature
• Performance improvement
• Documentation change with concrete technical impact
• Style, wording, formatting, or typo-only change

Why is this change needed?

A struct with a field named value would cause the #[derive(Hash)] macro to emit code where the local variable let value = ... shadowed the value parameter of update_state, producing broken generated code. Likewise, a field named serialized in a #[derive(Serde)] struct would shadow the ref serialized parameter in the generated deserialize function.

What was the behavior or documentation before?

Generated Hash::update_state code used let {field_name} = ... and then referenced {field_name}.value, which broke when field_name was value. Generated Serde::deserialize code used let {field_name} = ..., which broke when field_name was serialized.

What is the behavior or documentation after?

Generated locals are now named __hash_derive_member_{field_name} and __serde_member_{field_name} respectively, preventing any shadowing of reserved parameter names regardless of what the struct fields are called. Tests covering StructWithValueFieldForHash and StructWithSerializedField are added to confirm correct round-trip behavior.

Related issue or discussion (if any)

#10115 #10116

Additional context

All existing snapshot test data files have been updated to reflect the new generated variable names.