Transcribe with Mistral in Daytona

[alan747271363-art]

Summary

• add a long-form Daytona guide for running Sapat with Mistral Voxtral transcription
• add a speech-to-text provider definition
• add a first-time author profile and workflow SVG
• link the companion Sapat provider implementation: Add Mistral transcription provider nibzard/sapat#16

/claim #13

Validation

px.cmd markdownlint articles/20260514_transcribe_with_mistral_sapat_daytona.md definitions/20260514_definition_speech_to_text_provider.md authors/alan.md

• PowerShell XML parse for �rticles/assets/20260514_transcribe_with_mistral_sapat_daytona.svg
• git diff --check

Note: I also tried a full-repo markdownlint command with Windows-friendly quoting. It reports pre-existing lint issues in older unrelated files, while the files in this PR pass targeted lint.