Add optional codeSelection property and refactor feedback comment

[benibenj]

No description provided.

[Copilot]

Pull request overview

Adds support for carrying an optional code snippet alongside agent feedback attachment items, and refactors the Sessions “agent feedback” hover to render that snippet directly instead of trying to synchronously read editor models.

Changes:

• Extend IAgentFeedbackVariableEntry.feedbackItems[] with an optional codeSelection?: string.
• Refactor AgentFeedbackHover to use codeSelection for the hover code block and remove dependency on IModelService.
• Populate codeSelection from the attachment contribution’s snippet cache when constructing the attachment entry.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/vs/workbench/contrib/chat/common/attachments/chatVariableEntries.ts	Adds optional codeSelection to agent feedback attachment item shape.
src/vs/sessions/contrib/agentFeedback/browser/agentFeedbackHover.ts	Uses codeSelection to render snippet in hover; removes model/range dependency.
src/vs/sessions/contrib/agentFeedback/browser/agentFeedbackAttachment.ts	Passes cached snippet into feedbackItems[].codeSelection when building attachment entry.