CLI #7 of the series. Cursor stores its OpenAI key + "Override OpenAI Base URL"
in an opaque SQLite DB (state.vscdb) with no stable schema — not safe to
file-write. So `omniroute setup-cursor` prints the exact in-app steps and lists
real model names from /v1/models.
- Resolves apiBase WITH /v1 (Cursor appends /chat/completions) + key from
--remote/--api-key → active context → localhost.
- Prints Settings → Models → Override OpenAI Base URL + key + model-name steps,
with a clear caveat that the custom base URL powers Cursor's CHAT panel only
(Composer / inline-edit / autocomplete stay on Cursor's backend).
Researched against current Cursor behavior. Tests: resolveCursorTarget (/v1, key),
buildCursorInstructions (base URL + /v1 note + model samples + caveat). 4 unit
tests; check:cli-i18n green.
