docx metadata reveals whether a file was agent-generated

When asked "did we make this file together in a past session", grepping transcripts by keyword is not enough — hits can be base64 noise or mere directory listings, so check each match's context. Stronger evidence: unzip the docx and read docProps/core.xml + app.xml — Application (Microsoft Office Word vs none), creator, revision count, and TotalTime editing minutes distinguish hand-authored-in-Word from python-docx/agent-generated files. Cross-check the file's creation timestamp against transcript timestamp coverage: a session-activity gap over that window is near-conclusive the file was made outside the CLI (though web/desktop chats leave no local trace, so state that caveat).