fix: dataclasses as dictionary keys

[15r10nk]

Description

Related Issue(s)

closes #363

Checklist

• I have tested my changes thoroughly (you can download the test coverage with hatch run cov:github).
• I have added/updated relevant documentation.
• I have added tests for new functionality (if applicable).
• I have reviewed my own code for errors.
• I have added a changelog entry with hatch run changelog:entry
• I used semantic commits (feat: will cause a major and fix: a minor version bump)
• You can squash you commits, otherwise they will be squashed during merge

[Copilot]

Pull request overview

This PR fixes snapshot corruption when dictionaries use dataclass instances (and similar “call-represented” objects) as keys by ensuring Custom* wrapper objects don’t accidentally collapse as dict keys. It also adjusts tuple fixing to be positional (rather than alignment-based) so expressions are preserved more predictably when tuples grow/shrink.

Changes:

• Make multiple Custom* dataclasses use eq=False so they rely on Custom.__eq__/__hash__ (instead of dataclass-generated equality/hash), preventing key-collapsing in CustomDict.
• Add a dedicated positional compare_CustomTuple implementation and expand tuple-related adapter tests.
• Add a regression test for dataclasses as dict keys and update CI + changelog fragment.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/inline_snapshot/_customize/_custom_call.py	Prevent dataclass-generated equality/hash on CustomCall/CustomDefault (critical for dict-key behavior).
src/inline_snapshot/_customize/_custom_dict.py	Prevent CustomDict from getting dataclass equality/hash that can cause collisions.
src/inline_snapshot/_customize/_custom_external.py	Align CustomExternal equality/hash behavior with Custom base class.
src/inline_snapshot/_customize/_custom_unmanaged.py	Align CustomUnmanaged equality behavior with Custom base class.
src/inline_snapshot/_customize/_builder.py	Add a guard to detect key-collapsing during create_dict().
src/inline_snapshot/_new_adapter.py	Split tuple comparison into a dedicated positional implementation.
tests/adapter/test_dataclass.py	Regression test for dict snapshots with dataclass keys (issue #363).
tests/adapter/test_sequence.py	Add new tuple fix/update tests for the adapter behavior.
tests/test_preserve_values.py	Update expectations and reduce generic brace coverage to exclude tuples.
changelog.d/20260423_172841_15r10nk-git.md	Add changelog entry for the fixes.
.github/workflows/ci.yml	Update CI matrix to use pypy3.11 instead of older PyPy versions.