Wrong diff is shown after git pull during session

[roblourens]

• Do some edits in chat
• Do a git pull in terminal
• Do some more edits
• The edit session diff includes all the changes from git pull as green lines + the few lines that were actually edited by chat

The last edit in this request was fairly small

90014b84.copilotmd

The correct diff is like this, from SCM

But if I click the edit entry I see all this stuff from a commit that I just pulled

[connor4312]

This can happen if the pulled changes caused 'edits' in regions that the agent touched. In this case we combine those edits with those attributed to the agent.