[FEATURE] Add Support for Bengali (Bangla) in Auto-Captioning

Problem

The auto-captioning feature currently does not support the Bengali (Bangla) language. Bengali is the 6th or 7th most spoken language globally, and adding support is critical for creators in the South Asian region.

Solution

Since OpenCut utilizes OpenAI's Whisper (or Faster-Whisper) for speech-to-text transcription, supporting Bengali is technically feasible as Whisper already includes the bn language model.

Alternative

UI: Add "Bengali" or "Bangla" to the language selection dropdown in the Auto-Captioning/Transcription menu.

Backend: Ensure the transcription engine passes the language="bn" parameter to the Whisper model.

Font Support: Verify that the default caption renderer supports Unicode Bengali script to prevent "tofu" (broken characters) during rendering.

Anything else?

No response

Locate the Auto-Captioning/Transcription language selection dropdown and the Whisper or Faster-Whisper transcription integration. Check how the Bengali language option maps to bn and whether the default caption renderer displays Unicode Bengali without tofu. Done means Bengali is selectable, transcription uses bn, and rendered captions display correctly.