fix jump in terminal headers

[justschen]

fix #297989

[Copilot]

Pull request overview

Fixes a UI layout “jump” in chat terminal invocation headers by adjusting styling in the chat thinking content stylesheet (ref: #297989).

Changes:

• Aligns terminal collapsible header button content using flex layout to prevent height/position shifts.
• Refactors the .chat-thinking-tool-wrapper / .chat-used-context styling block (structure + additional flex alignment).

Comments suppressed due to low confidence (1)

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/media/chatThinkingContent.css:129

• This nested selector will likely compile to .monaco-button.monaco-text-button .monaco-button:hover .chat-collapsible-hover-chevron, which won’t match the hover chevron inside the same button. Consider changing it to &:hover .chat-collapsible-hover-chevron (and/or moving the rule outside) so the chevron opacity updates on hover as intended.

					.monaco-button:hover .chat-collapsible-hover-chevron {
						opacity: 1;
					}