VSCode: Per-tab activity indicator (working vs. idle) for multiple Claude Code sessions

What I'm trying to do

I run multiple Claude Code sessions in separate VS Code editor tabs (typically ~5 at once). When I glance at the tab bar, I can't tell which sessions are actively processing and which are idle or waiting.

Current behavior

The spark icon shows a couple of states via colored dots:

• Blue dot when a permission request is pending
• Orange dot when a session finished while its tab was hidden

But there is no indicator for the active/processing state. A tab that's mid-response looks identical to one sitting idle. The only way to know a tab is busy is to click into it.

What I'd like

An animated activity indicator on the tab itself (spinner, pulsing icon, or similar) while a session is processing, the same way the in-session "thinking" indicator communicates activity. The goal is an at-a-glance answer to "which of my open tabs are working right now?" without switching between them.

Why

With several concurrent sessions, switching tab-by-tab to check status is the main friction. A per-tab busy/idle distinction would make managing parallel sessions far easier. claude agents in a terminal gives a Working / Needs-input / Completed view, but it lives outside VS Code and doesn't map to the tabs I'm actually working in.

Prior context

This has come up before and the related issues were all closed as "not planned" due to inactivity, not a design decision (the maintainer explicitly invited refiling):

• #26211 — Live status indicators in session list (VSCode sidebar)
• #28147 — Activity indicators for multi-session navigation
• #34054 — Read/unread indicator for conversations
• #34309 — Loading/spinner indicator on tabs while processing (closed as dup of #26211)