docs(openai): fix AzureModelMapperFunc doc comment to match actual behavior

[icn5381]

References

References #939

Why

AzureModelMapperFunc's doc comment claims the default mapper strips [,:] (comma/colon) from the deployment name, but the actual default implementation in the underlying go-openai client strips [.:] (dot/colon). A caller passing a real Foundry deployment name containing a dot (e.g. gpt-5.6-luna) gets it silently rewritten, resulting in a 404 with no hint that the client transformed the name.

What changed

Fixed the doc comment in three places to say [.:] instead of [,:], matching what the code actually does:

• libs/acl/openai/chat_model.go
• components/model/openai/chatmodel.go
• components/model/openai/README.md

This is a comment/doc-only change (option 2 from the issue's three suggestions) — the least controversial fix since it doesn't change runtime behavior, unlike options 1 (stop transforming by default) or 3 (add debug logging), which the maintainer hasn't weighed in on yet.

Surface area

• Docs / tests / CI only

Validation

gofmt -l on the two changed .go files reports no issues. go build in the affected modules currently fails in this environment due to a pre-existing bytedance/sonic / Go 1.26 incompatibility unrelated to this change (comment-only edit, no code logic touched).

AI assistance

• Tool(s) used: Claude Code
• How you used it: AI helped locate all doc-comment occurrences of the mismatched regex description across the repo and drafted the fix.
• Human verification: Read and understood every line of this change; confirmed via grep that all three occurrences of the stale [,:] comment were found and fixed consistently; confirmed the change is comment-only with no behavioral impact; take responsibility for this change.
• I've read and understand every line of this change and take responsibility for it.