ci(local-model): hold a row that names its runner to the build a Mac pulls

The catalogue that names each row's runner (feat/local-model-catalog-v2: `runner` is `mlx` or
`llamacpp`, and a row's memory figures follow that runner's rule) needs the weekly check to
notice when a tag starts serving a Mac another runner: a tag that gains an mlx child, or a
list that loses it. The size check usually catches that, but not when the two builds come out
about the same size, and the figures are wrong either way.

classifyModel() now raises a `runner` finding when the row names a runner and the build a Mac
selects runs on another one. catalogueRunner() maps the registry's names into the catalogue's:
`mlx` stays `mlx`; `llamacpp`, and `ggml` (what Ollama calls a GGUF manifest that names no
runner), are `llamacpp`, because Ollama 0.40.15 serves every GGUF build through llama-server.
A catalogue without the field (the one on this branch today) is never held to a runner.

Run live on 2026-11-08 against the v2 catalogue's eight rows: exit 0, every runner matches.
Tests: the mapping, the finding (both directions, ggml, an unknown runner, a row without the
field), the report text, and runCheck against the fake registry with a plain GGUF manifest.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/local-models.md

@@ -270,6 +270,10 @@ For every model row it checks:
   Ollama asks, picks the build a Mac picks and sizes it the way a pull counts it (every layer
   plus the config). The plain manifest other tools get for the same tag is the `llamacpp`
   build, which is not what a Mac downloads.
+- **The runner of that build**, once a row names its `runner`: a Mac still pulls an `mlx`
+  build for an `mlx` row and a GGUF build (`llamacpp`, or a manifest that names no runner)
+  for a `llamacpp` row. A row's memory figures follow its runner, so a tag that gains or
+  loses an mlx build is drift even at about the same size.
 - **The build a Mac pulls runs on the pinned runtime**: its config declares no newer
   Ollama (`requires`) than `OLLAMA_RUNTIME_PIN`.
 - **The pinned digest**, once a row carries one: a Mac would still pull that manifest. The