Remove physicsnemo compatibility layer

[coreyjadams]

PhysicsNeMo Pull Request

We are now in version v2.3, it is safe to remove the v2.0 compatibility shims.

Description

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• The CHANGELOG.md is up to date with these changes.
• An issue is linked to this pull request.
• If I am implementing a new model or modifying any existing model, I have followed the Models Implementation Coding Standards.

Dependencies

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[github-actions]

CODEOWNERS review map

Current for commit 62ba7487e85e. An approval covers every file listed for that owner; one owner is sufficient for shared files.

⏳ @megnvidia — 1 file(s)

• v2.0-MIGRATION-GUIDE.md

⏳ @ram-cherukuri — 1 file(s)

• v2.0-MIGRATION-GUIDE.md

No CODEOWNER

• .importlinter
• CHANGELOG.md
• physicsnemo/init.py
• physicsnemo/compat/init.py
• skills/physicsnemo-discover/references/RECIPES.md
• test/compat/init.py
• test/compat/test_compat.py

Comment /codeowners-info to refresh.

[greptile-apps]

The code removal appears safe to merge, but the migration documentation and discovery fallback should be corrected so users can reliably translate removed import paths.

Findings

1.  Missing Rename Tables ▶
2.  Function Fallback Uses Class Placeholder ▶

Summary

This PR removes the opt-in pre-v2.0 import compatibility layer, its activation environment variable, import-linter configuration, and dedicated tests. It also updates release and migration documentation plus the discovery skill’s renamed-API fallback.

• The compatibility implementation and all remaining in-repository callers are removed consistently.
• The migration guide does not retain the deleted old-to-new mapping data despite directing users to rename tables.
• The discovery recipe’s shared class/function fallback uses a class-only placeholder.

_{Reviews (1) · Last reviewed commit: "Remove physicsnemo compatibility layer f..."}

[ktangsali]

LGTM! Just a minor comment.

[coreyjadams]

/ok to test c948086

[megnvidia]

approve pending accepting suggested changes

[coreyjadams]

/ok to test fab4609