Edit the spreadsheet inside the ticket

A spreadsheet opened from a ticket is still the ticket. Agents edit .xlsx in place. Customers can receive the workbook, or a PNG of a drawing, without a side channel.

Sheet Edit treats the attachment as the source of truth. Every save uploads a new file and bumps a version. Version 1 is never rewritten. A stale save asks you to reload or force the write.

Drawing Edit follows the same turn-based rule for Excalidraw scenes. The scene JSON is the attachment. A PNG preview rides along so the rest of the thread can see the picture without opening the editor.

Work in place is not a nested app. It is one more owned node on the rail that already holds the replies, the files, and the handoff notes.