その他のファイル形式が読み込めない。Files uploaded as "Other file types" cannot be read by the LLM.

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### Dify version

1.16.1

### Cloud or Self Hosted

Self Hosted (Docker)

### Steps to reproduce

開始ノードで単一ファイルの変数を作成し、その他のファイル形式として設定します。 その変数をLLMノードに渡しても中身を確認することができないようです。 単一ファイルの変数を画像や音声に設定すると、ファイルの中身が読むことができます。

1. Create a **Single File** variable in the Start node.
2. Set the supported file type of the variable to **Other File Types**.
3. Pass the Single File variable to an LLM node.
4. Upload a file and run the workflow.
5. The LLM appears to be unable to read or access the contents of the uploaded file.

### ✔️ Expected Behavior

その他のファイル形式を選んだ場合でも、LLMが内容を確認できる。

The LLM should be able to read and access the contents of the file even when "Other File Types" is selected.

### ❌ Actual Behavior

その他のファイル形式を選んだ時だけ、LLMがファイルの中身を確認できない。
これはクラウド版でもDocker版でも発生します。

The LLM cannot read the contents of the file only when "Other File Types" is selected. This issue occurs in both the Dify Cloud version and the self-hosted Docker version.

Reproduce the workflow using a Start-node Single File variable set to Other File Types and pass it to an LLM node, as described in the issue. Trace how that file type is handled between the Start and LLM nodes in both cloud and Docker deployments; the work is done when the LLM can access the uploaded file contents for Other File Types.

Written by the indexing model from the issue text.