Document Codex Ollama base URL normalization

Update the README and API guide to reflect the shared core behavior
for Codex/Ollama base URLs.

Root Ollama URLs are now normalized to the OpenAI-compatible /v1
endpoint, so the docs now describe the stable contract that the
shared subprocess core enforces.

Author: nshkrdotcom

README.md

@@ -188,9 +188,10 @@ The SDK does not infer those flags on its own.
 - CLI argument rendering only emits `--model` from a non-empty resolved value
 
 If `ollama_base_url:` is supplied, that endpoint is carried inside the
-payload-owned env overrides as `CODEX_OSS_BASE_URL`. The exec and app-server
-transports both consume that payload data directly instead of keeping a second
-raw base-url path alive downstream.
+payload-owned env overrides as `CODEX_OSS_BASE_URL`. Raw Ollama roots are
+normalized to the OpenAI-compatible `/v1` base before those env overrides are
+emitted. The exec and app-server transports both consume that payload data
+directly instead of keeping a second raw base-url path alive downstream.
 
 When the chosen local model is outside Codex's built-in model metadata catalog,
 the upstream CLI may warn that it is using fallback metadata. That is an

guides/03-api-guide.md

@@ -228,8 +228,9 @@ That matters most on the local Ollama route:
 - conflicting raw attrs fail during normalization instead of being silently
   reinterpreted in the SDK
 - a custom Codex/Ollama base URL is carried inside payload env overrides as
-  `CODEX_OSS_BASE_URL`, so exec and app-server transports can rely on the
-  payload alone after normalization
+  `CODEX_OSS_BASE_URL`. Raw Ollama roots are normalized to the
+  OpenAI-compatible `/v1` base, so exec and app-server transports can rely on
+  the payload alone after normalization
 
 `connect/2` also accepts `oauth:` for child-auth-aware startup: