Codex App: honor generated/context file attributes in local change counters and diffs

Summary

Codex App for Mac appears to include repository workflow/context artifacts marked as generated in the local change counter and change diff view. It would be useful if Codex App honored .gitattributes metadata such as linguist-generated, or provided an equivalent path/attribute-based way to classify files as workflow context rather than source changes.

Use case

Some projects keep agent workflow/context files in Git so that new checkouts and worktrees have the same project context available to Codex agents. These files are intentionally versioned, but they are not source/runtime changes. Examples include planning cycles, research notes, decision logs, and agent handoff files.

When these files are updated, Codex App currently appears to count them like ordinary source changes, which creates noise in the local change counter and makes it harder to see the actual source/test/config diff.

Reproduction

1. Add .gitattributes entries similar to:

AGENTS.md agent-instructions
_devflow/git.md agent-instructions
_devflow/project.md agent-instructions
_devflow/subagents.md agent-instructions

_devflow/** devflow-artifact linguist-generated
_devflow/git.md -devflow-artifact -linguist-generated
_devflow/project.md -devflow-artifact -linguist-generated
_devflow/subagents.md -devflow-artifact -linguist-generated

1. Confirm Git sees the generated/context attributes:

git check-attr -a -- _devflow/research/example.md

Result:

_devflow/research/example.md: devflow-artifact: set
_devflow/research/example.md: linguist-generated: set

1. Create an untracked or modified file under _devflow/research/example.md.
2. Observe the Codex App for Mac local changes counter.

Actual behavior

The local changes counter increases for the file even though it is marked linguist-generated and classified as a workflow/context artifact.

Expected behavior

Either:

• Codex App honors linguist-generated similarly to GitHub's generated-file diff behavior, or
• Codex App provides a Codex-specific way to classify paths/attributes as agent workflow context so they can be separated from source/runtime changes in local counters and diffs.

A good implementation could still keep these files visible somewhere, but separate them from source/test/config/CI changes so agents and users can focus on behavior-changing diffs.

Why this matters

For agent-oriented repositories, versioned context files are useful and often necessary. They allow fresh Codex sessions or worktrees to inherit project state. But treating those context artifacts exactly like source changes adds review noise and makes the local diff signal weaker.