"Produce from Document" fails with FileSystemError when source is a Kafka message preview

[eguicf]

Description

When attempting to use the "Produce from Document" command on a message that was opened via the Kafka message preview (using the confluent.topic.message: URI scheme), the operation fails with a FileSystemError.
The extension incorrectly passes the full custom URI (e.g., confluent.topic.message:c:\Users...\file.json?{...}) to VS Code's filesystem API, which cannot resolve this mixed URI format.

Sentry links

• Windows
• macOS

[shouples]

The main issue seems to be here:

vscode/src/documentProviders/index.ts

Line 28 in f0d4b78

path: join(homedir(), filename),

Where the resulting URI ends up looking like confluent.topic.message:/path/to/file?... (Linux) or confluent.topic.message:c:\path\to\file (Windows), which isn't valid.