Hide models contributed by background agents

[DonJayamanne]

No description provided.

[Copilot]

Pull request overview

This PR aims to hide language models that are contributed for specific (background/contributed) chat session types from general UX surfaces, so users only see “general” models unless they are in the appropriate session context.

Changes:

• Filter prompt-header model autocompletions to exclude models with targetChatSessionType.
• Add a canManageModels() capability to the model picker delegate and use it to conditionally show model-management actions in the picker’s action bar.
• Wire the new delegate capability in ChatInputPart.

Reviewed changes

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

File	Description
src/vs/workbench/contrib/chat/common/promptSyntax/languageProviders/promptHeaderAutocompletion.ts	Excludes session-targeted models from prompt header model completions.
src/vs/workbench/contrib/chat/browser/widget/input/modelPickerActionItem.ts	Adds canManageModels() to the delegate and gates the picker action bar provider.
src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts	Implements canManageModels() for the picker delegate based on current session type.