machinewrapped/llm-subtrans — reverse-engineered prompt

Build me an open source desktop tool for translating subtitle files with AI. I want to open a subtitle file like SRT, ASS, SSA, or VTT, pick the source and target language, choose an AI provider, enter my API key, and get a translated subtitle file back while keeping the timings and formatting intact.

It should have a simple GUI for normal users, plus a command line option for people who want to automate it. Support common providers like OpenRouter, Gemini, OpenAI, DeepSeek, Anthropic, Mistral, and OpenAI compatible custom servers. Let me choose a model when needed, or use a default option if the provider supports it.

Please include basic first run settings, clear error messages, progress while translating, and a warning that subtitles are sent to the selected provider online. Make it installable from source with Python, and structure it so new subtitle formats or providers can be added later.