One item. One folder.
A copied or downloaded source is stored as original.*. Later Actions write new files. They do not modify that source. Reveal the Library or an item folder in Finder whenever you want to inspect or move the useful parts.
Search the words and the idea
Exact search covers titles, transcripts, notes, outputs and source information. Meaning search runs locally over transcript passages and can take a strong match back to its timestamp.
The files remain the record
Media Mill keeps a SQLite search index and local embeddings for speed. Those are rebuildable caches. Item folders remain the source of truth.