Track packaged install breakage from hardcoded RCS_PREFIX #284

Summary

python/rcs/__init__.py currently sets:

RCS_PREFIX = os.path.join(os.path.dirname(__file__), "../../")

This works for editable installs, but it likely breaks standard wheel / non-editable installs because the resolved path escapes the installed package root and no longer points at packaged assets/.

Why this matters

Import-time asset resolution can fail for users who install via pip install . or from a built wheel, even though local editable development works.

Context

• Surfaced during review of PR refactor!: unify env/scenes API across robots and restructure assets #283
• Deferred on purpose so PR refactor!: unify env/scenes API across robots and restructure assets #283 can focus on the current CI / refactor work

Follow-up ideas

• package assets inside the Python package and resolve them with importlib.resources
• or restore/install asset-copying logic so runtime paths stay inside the installed package
• verify both editable and wheel installs in CI

Related PR: #283