Fix context handling in ChatWidget while re-editing

[tamuratak]

Fix context handling in ChatWidget while re-editing chat requests. currentElement.variables should be added to currentContext. Fix #281766.

[Copilot]

Pull request overview

This PR fixes context handling when re-editing chat requests by ensuring that both attachedContext and variables from the current request are included in the context when entering edit mode.

Key Changes

• Refactored inline filtering logic into a reusable addToContext helper function
• Added deduplication logic using a Set to prevent duplicate context entries when combining attachedContext and variables
• Fixed bug where currentElement.variables was not being added to the editing context

[justschen]

this looks like it's going in the right direction, but still has some issues with files attached via #

this is a good change regardless, thank you