[Triage] Error 500 language becomes nil

[igorbaikov]

Describe the bug
I get error 429 on some videos if I set subtitle languages to ru,en. That's a known bug. However, what's more interesting is if I also set ytdlp options to ignore errors and still download video, it does download (subs are downloaded fine as well, in en in this case) but then it shows error 500 on the video page. On youtube that particular video only has autogenerated subs; and ru subs are autotranslated from the generated en subs. I think it might fix error 429 as well?

**Reason**:
`%ArgumentError{message: "cannot convert the given list to a string.\n\nTo be converted to a string, a list must either be empty or only\ncontain the following elements:\n\n  * strings\n  * integers representing Unicode code points\n  * a list containing one of these three elements\n\nPlease check the given list or call inspect/1 to get the list representation, got:\n\n[\"ru\", nil]\n"}`

To Reproduce
Steps to reproduce the behavior:

Find a video that throws error 429 if subs are set to two languages (ru,en for example). Add option -i to yt-dlp base-config. Download video, you'll get err 500 on video page.

Expected behavior
To show up the video page just fine, cuz the video and subs are both loaded, there shouldn't be an error. Perhaps it could fix 429 and download the subs that are prioritized (ru) in my case?

Screenshots
If applicable, add screenshots to help explain your problem.

Diagnostic info

- App Version: 2025.9.26
- yt-dlp Version: 2025.10.14
- Apprise Version: v1.9.4
- System Architecture: x86_64-pc-linux-gnu
- Timezone: Europe/Moscow

Status:
500

Reason:
%ArgumentError{message: "cannot convert the given list to a string.\n\nTo be converted to a string, a list must either be empty or only\ncontain the following elements:\n\n * strings\n * integers representing Unicode code points\n * a list containing one of these three elements\n\nPlease check the given list or call inspect/1 to get the list representation, got:\n\n[\"ru\", nil]\n"}

Stacktrace:

    (elixir 1.18.4) lib/list.ex:1124: List.to_string/1
    (elixir 1.18.4) lib/enum.ex:4192: Enum.join_non_empty_list/3
    (elixir 1.18.4) lib/enum.ex:4468: Enum.join_list/2
    (pinchflat 2025.9.26) lib/pinchflat_web/components/core_components.ex:637: anonymous fn/1 in PinchflatWeb.CoreComponents."list_items_from_map (overridable 1)"/1
    (elixir 1.18.4) lib/enum.ex:1714: Enum."-map/2-lists^map/1-1-"/2
    (elixir 1.18.4) lib/enum.ex:1714: Enum."-map/2-lists^map/1-1-"/2
    (pinchflat 2025.9.26) lib/pinchflat_web/components/core_components.ex:636: PinchflatWeb.CoreComponents."list_items_from_map (overridable 1)"/1
    (phoenix_live_view 1.0.17) lib/phoenix_live_view/tag_engine.ex:96: Phoenix.LiveView.TagEngine.component/3