Add a "your recordings" retention configuration step between observers (step 4) and get started (step 6) in the first-time setup wizard. Users choose between keep-forever, keep-N-days, and delete-after- processing modes with day presets (7/30/90/custom). finalize() includes retention_mode and retention_days in the POST payload; init_finalize() writes them as retention.raw_media and retention.raw_media_days to journal.json. Default is days/7 when untouched. Remove the hard-coded retention paragraph from the welcome screen since users now configure retention during setup.