make sure hook is shown in collapsed title for subagent and thinking

[justschen]

fixes issue where hooks wouldn't be shown in thinking and subagent titles when they were shown in the dropdown

[Copilot]

Pull request overview

This PR fixes an issue where hook messages (blocked tools or warnings) were not being shown in the collapsed titles of thinking and subagent sections, even though they were visible in the dropdown when expanded.

Changes:

• Modified thinking part title update logic to allow hook titles to be displayed after response completion
• Added hook count tracking to inform LLM title generation about blocked/warned tools
• Updated subagent part to display hook messages in collapsed title immediately when hooks are appended
• Enhanced LLM title generation prompt to handle blocked/denied content appropriately

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts	Added hookCount tracking, modified setTitle to check generatedTitle instead of element.isComplete, updated LLM prompt to conditionally include hook-related guidance
src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatSubagentContentPart.ts	Added logic to appendHookItem to generate and display hook messages in the title before rendering the hook item

Comments suppressed due to low confidence (1)

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/chatThinkingContentPart.ts:1372

• The change from checking this.element.isComplete to this.content.generatedTitle creates a potential race condition. Consider this scenario:

1. Response completes, finalizeTitleIfDefault() is called
2. LLM title generation starts asynchronously via generateTitleViaLLM()
3. Hook arrives and calls setTitle() with hook message (line 1235 in trackToolMetadata) - this succeeds because generatedTitle is not set yet
4. LLM title generation completes, sets this.content.generatedTitle and calls super.setTitle() (line 918), overwriting the hook title

The hook title would be briefly displayed then immediately overwritten. A more robust solution would be to:

• Track whether title finalization has started with a boolean flag
• Only allow hook-related updates after finalization starts
• Or, better yet, include hook information in the context passed to generateTitleViaLLM() so hooks are incorporated into the generated title

	protected override setTitle(title: string, omitPrefix?: boolean): void {
		if (!title || this.element.isComplete) {
			return;
		}

		if (omitPrefix) {