52eb8eb533
Adds a pre_transcription transform hook (prompt/language/model mutable, file_path read-only, last-writer-wins per the transform_* convention) fired before any STT backend, threads prompt to faster-whisper (initial_prompt) and OpenAI/Groq/Mistral/DeepInfra (prompt), adds an optional stt.prompt config key on the same plumbing, and keeps the no-hook dispatch path byte-identical. Fixes #64168. Documents the new surface for users: a "Transcription prompt (vocabulary hints)" subsection in the configuration guide (composition order, per-provider support matrix, length contract, privacy warning), a pre_transcription entry in the hooks reference, and the mirrored row in the plugins hook table. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AG6LyYMvHC2o6HbVUozmVR