scripts/setup.sh step 5/7 reports [ok] after the model cache failed #537

Problem

Step 5/7 of scripts/setup.sh prints a success label even when the pre-cache failed.

Observed verbatim during an install on 2026-09-09:

=== [5/7] Embedding model ===
  Pre-caching sentence-transformers model (one-time ~100MB download)...
  [\] running...  [|] running...  [/] running...Warning: model cache failed (
  ...
  Original error was: No module named 'numpy._core._multiarray_umath'
). Will download on first use.
[ok] Embedding model cached

The model was not cached. The [ok] line contradicts the warning printed immediately above it.

Why it matters

Falling back to a lazy download on first use is a reasonable design, so the step should not be fatal. But the label must say what happened. As written, a reader scanning for [ok] lines concludes the cache is populated when it is not, and the real cause (here a stale numpy extension built for another interpreter) scrolls past unread.

Suggested fix

Distinguish the two outcomes. Report [ok] Embedding model cached only when the pre-cache actually succeeded, and something like [warn] Model not pre-cached, will download on first use otherwise. The step stays non-fatal either way.