Ten tasks in a fixed order: land reasoning_tokens first so it can serve
as the acceptance instrument for the thinking-switch fix, then reshape
the provider profile, add the model-level capability table, wire the
assembly guard, fold enable_thinking into the cache fingerprint, and
verify the whole thing against the live API.
Incorporates a read-only Codex review: resolve_thinking now takes the
model name so its errors can name it, and the warning assertion uses a
loguru sink because caplog cannot see loguru output.
