Step 0 of docs/plans/2026-10-provider-refactor.md. provider-matrix.test.ts
snapshots what getAIModel hands to each SDK factory, and what
usesServerCredentials, usesServerEndpoint, globalBaseUrl and chatRequestUrl
answer, for 24 providers, 15 client override shapes and 9 server
environments, plus auto-detection rows and model id probes (3879 rows).
provider-legacy.test.ts keeps a copy of the two quota functions and compares
them with the live ones over every input class (30720 and 288 combinations).
No production code changes.
