Show failure reason on failed collection file indexing

[Raymond9734]

Hey 👋 I’m Raymond Madara

While testing the Voyage AI embeddings integration (#1952), I ran into something that felt like a rough edge worth discussing.

When a file fails to index whether it's a rate limit, a bad API key, or a network hiccup the UI just shows a red "Failed" badge next to the file. There's no indication of why it failed. The error is logged in Celery, but it never makes it back to the user.

In my case, Voyage AI was hitting a rate limit (free tier, 3 RPM). The files kept failing and I had no idea from the UI, I had to dig through Docker logs to figure it out. A user without access to logs would be completely stuck.

What I'd suggest

• Add a failure_reason field (TextField, blank=True) to CollectionFile
• Store the exception message when indexing fails in LocalIndexManager.add_files()
• Show it in the UI, even just a tooltip on the failed badge

This affects all providers (OpenAI, Google, Voyage AI) any failure is currently silent.

cc: @SmittieC and @snopoke

[snopoke]

@Raymond9734 thanks for reporting this. We do already have an issue for tracking this improvement so I'm going to close this as a duplicate (but I've copied some of your content to the other issue).

The other issue is #3164

[Raymond9734]

Glad to hear it’s already being tracked 👌