What was done

1. Root cause identified. defaults read com.apple.screencapture location returned the literal string ~/Library/Mobile Documents/com~apple~CloudDocs/Screenshots Mac. macOS does not expand ~ in this preference, and the folder also did not exist. Invalid path = silent fallback to Desktop. This explains every screenshot landing on the home screen.
2. Cleanup. Created /Users/samaguiar/Library/Mobile Documents/com~apple~CloudDocs/Screenshots Mac and moved all 116 Screenshot * files from ~/Desktop into it. Desktop now has 0 screenshots; destination has 116; iCloud confirmed syncing up.
3. Permanent fix. defaults write com.apple.screencapture location rewritten with the absolute path, SystemUIServer restarted, value read back and path validated as an existing directory.
4. Rollback. Move manifest with every filename at ~/Documents/Projects/admin/file-ops-logs/screenshot-desktop-cleanup-2026-06-04.txt. Rollback is mv each listed file back to ~/Desktop/. Reverting the setting: defaults delete com.apple.screencapture location restores the macOS default (Desktop).
5. QA. Sampled every 10th moved file (12 of 116), all present at destination. Defaults value verified absolute and valid. Work done via Desktop Commander (host Mac) since the Cowork sandbox cannot run defaults on the host. (sandbox: desktop-commander fallback, cowork host-control case)

Why the session ended

Task complete.

Recommended next actions

• Nothing required. Future screenshots (Cmd+Shift+3/4/5) will save to the iCloud Screenshots Mac folder and sync across devices.
• Optional: a small scheduled task could watch for screenshot regrowth on Desktop (catches macOS updates resetting the pref) — offered to Sam inline, pending his choice.
• Optional: rename-images skill could give the 116 files descriptive names; offered inline.

Handoff notes for future agents

• If screenshots ever pile up on Desktop again, first run defaults read com.apple.screencapture location and check the path is absolute AND the directory exists. Literal ~ in this pref is the classic failure. Always write it with $HOME expanded.
• The chosen destination is in iCloud Drive; if Sam's iCloud storage fills, screencapture may fail to write there. A local fallback like ~/Pictures/Screenshots is the alternative.
• Tasks status: all done. No deferrals.

Importance: Low. Tasks: mark done.

Update (2026-06-08) — final state after Sam's follow-up choices

Sam chose all three self-audit follow-ups (local folder, rename, drift guard). Final state:

• Save location changed to local: /Users/samaguiar/Pictures/Screenshots (no longer the iCloud folder, which was created then emptied and removed). defaults read com.apple.screencapture location confirms the absolute local path. Avoids iCloud storage use and sync delay.