fix: exclude chatgpt-4o-latest from OpenAI catalog

[jaswdr]

OpenAI retired API access to chatgpt-4o-latest on February 16, 2026. Adding it to exclude_models prevents downstream apps from surfacing a model that returns 404 model_not_found at runtime.

Description

• Added chatgpt-4o-latest to the exclude_models list in priv/llm_db/providers/openai.json, consistent with how other retired/unsupported OpenAI models (o1-preview, o1-mini, etc.) are already handled.
• Removed the chatgpt-4o-latest model entry from the models map in priv/llm_db/providers/openai.json so the backfill history engine emits a removed event, keeping the history record accurate.
• Rebuilt priv/llm_db/snapshot.json to reflect the removal.

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Breaking Changes

N/A

Testing

• Tests pass (mix test)
• Quality checks pass (mix quality)

Checklist

• My code follows the project's style guidelines
• I have updated the documentation accordingly
• I have added tests that prove my fix/feature works
• All new and existing tests pass
• My commits follow conventional commit format
• I have NOT edited CHANGELOG.md (it is auto-generated by git_ops)
• I have NOT directly edited generated snapshot/history artifacts unless this PR intentionally regenerates them (priv/llm_db/snapshot.json, priv/llm_db/history/**)

Related Issues

Closes #171

[mikehostetler]

@jaswdr thanks for doign this - we should modify the local TOML files instead of the OpenAI JSON file - otherwise this won't get persisted after the database rebuilds

[jaswdr]

addressed 👍