Workpaper & Chat Reliability Fixes

Sum calculator restored in the cell detail panel: When working with cells that sum values across a document, the yellow Σ total display and calculator had disappeared from the right-hand panel. It's now back — clicking into a sum cell shows your running total, and you can adjust the sign of individual components or remove them directly from the panel.
Match automations running again: On some workpapers, the automated matching process was silently stopping before completing. This is now resolved — match columns run to completion as expected.
AI chat handles interrupted sessions more reliably: Two separate issues could cause the AI chat to stop responding — one when a tool action was cancelled mid-run, and one when a session was interrupted before completing. Both are fixed; resuming a chat after an interruption now works correctly.

"Create by Procedure" is no longer available: The task creation flow that accepted a procedures document and generated a suggested workflow from it has been removed. Tasks can still be created from templates, from scratch, or via the Financial Statement Review flow.