Codex Desktop may use a stale image-input revision when a PNG filename is reused

What issue are you seeing?

In Codex Desktop on Windows, an image supplied as an input attachment can be interpreted as an older version when the user replaces a PNG with a newer version that has the same filename.

The user opened a new Codex task and supplied a completed venue-render image that includes the ceiling. Codex nevertheless treated it as the earlier, ceiling-less version of that same named file. This has reportedly happened repeatedly.

This is not merely a stale preview of an assistant-rendered local Markdown image. It affects the image version used as the agent's visual input, so the assistant can make decisions from an obsolete source image.

A screenshot of the latest intended image was provided in the task: it visibly contains the ceiling. The mismatch between this current attachment and the older image that was described by the agent caused lost work and a strong loss of trust.

Steps that appear to reproduce the bug

1. Attach or use a PNG as image input in Codex Desktop.
2. Create a newer revision by overwriting/re-exporting it while retaining exactly the same filename.
3. Start a new Codex task.
4. Attach the new revision and ask the agent to inspect it.
5. Observe that the agent may reason about the earliest version instead of the newly attached revision.

Expected behavior

Each image input attachment must be identified and processed from its actual uploaded bytes (or a content hash), not a reusable filename/path/thumbnail cache key. A new task must not cause an old image revision to be used when a newer revision is attached.

Possible diagnostic/fix areas

• Client attachment deduplication/cache keys for local image inputs
• Any path-or-filename keyed preview/asset cache shared across tasks
• Image-upload and multimodal preprocessing identity; use a content hash or opaque upload ID
• Invalidate stale cache entries when the local file's mtime/size/content changes

Related issue

This may be related to #24446, which reports stale local image rendering when an assistant Markdown image path is reused. This report is intentionally separate because the reported impact is stale image input interpretation, not only stale rendering in the chat UI.

Environment

• Codex Desktop
• Windows
• Repeated behavior reported by the user
• Exact app version not captured in this report