Use this skill whenever working on the SpanishTransfer project or when asked to write, rewrite, or improve Spanish language lesson files. Triggers for: writing message.uk.md or message.en.md lesson files, improving reminder files, processing YouTube transcripts into lesson content, generating Language Transfer style lesson content, or any task involving lessons/NNN/ directories in the SpanishTransfer repo. Also triggers when user provides transcript.txt or transcript.formatted.txt files and asks to create lesson content from them.