Graphshell is pre-user. There is no production user base and no legacy data that must be preserved.

• Prefer deletion over compatibility shims, unless ensuring compatibility between existing, supported features or subsystems.
• Do not add migration branches for historical formats unless explicitly requested.
• Keep one active architecture path; avoid fallback product modes that split implementation unless necessary to ensure proper ux (e.g. managing failure states that don't require maintaining obviated code).
• Keep tests focused on current semantics and current persistence schema.

When older plans encode migration/legacy contingencies, either:

1. archive the old plan under a timestamped archive_docs/checkpoint_* folder, or
2. revise it in place to this policy.

This policy applies until superseded by an explicit product release and real-user migration requirement.