Investigate: is the import topology declared, enforced, and is the declaration itself checked?

[Polichinel]

What to check

Whether this repository's internal import topology is declared and enforced, and — the sharper question — whether anything that is declared is itself checked, rather than only being the thing the code is checked against.

Measured across all views_platform repos on 2026-08-18: 4 of 18 carry import cycles, 7 have some form of import-enforcement test, and only 1 has a declared topology contract.

This repo: 2 subpackages · 0 cycles · enforcement test: none

My assessment

Likely in order on imports; the declared-list question is the live one.

Two subpackages, zero cycles. Too small for a topology contract.

But this repo is built on declared dispatch — the 2026-02 ontology-liberation post-mortem replaced prefix inference with four canonical dispatch dicts (REGRESSION_POINT_METRIC_FUNCTIONS and siblings) and the lesson recorded was "the config is the contract." That makes it the most likely place on the platform for C-351's shape to bite.

Suggestions

1. Ask C-351 of the four dispatch dicts. Does anything assert that every metric named in config exists in exactly one dict? That the four are disjoint? That a metric in a dict is reachable from some valid config?
2. If evaluate() validates config against the dicts but nothing validates the dicts, that is precisely the shape.
3. Skip the import contract — two packages.

For examples / inspiration

• views-datafactory #457/#458 — test_the_declared_graph_is_acyclic and test_every_package_on_disk_is_declared. Two assertions in an existing file. No new dependency, no graph library, no new module. The insight is worth stealing verbatim: an assertion about conformance standing in for an assertion about the property.
• views-frames pyproject.toml [tool.importlinter] — two layers contracts, | between siblings meaning independent (that is what prevents a cycle; : permits one), each recording the direction the code already has. Note the comment explaining why the contract and tests/test_import_enforcement.py deliberately overlap.

Investigative issue filed by Claude Opus 5 at Simon's request, after a census of import structure across all views_platform repos. Nothing was changed in this repository.