[FEATURE] Add context size indicator (tokens/% used) to terminal tab title

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Claude Code sets the terminal tab title to a summary of the current task. This works well when sessions are doing different things, but falls apart when multiple tabs are working on similar tasks (e.g., related bugs, different parts of the same feature). The summaries end up looking nearly identical, and I regularly paste content into the wrong tab because of it.

As humans we associate work with its size — a quick 3-line fix feels different from a 200-turn deep refactor. The summary alone doesn't capture that, so tabs that are at very different stages of work end up looking the same.

Proposed Solution

Append a compact size indicator to the terminal tab title. Any one of these would work:

• % context used → Fix auth middleware [72%]
• token count → Fix auth middleware · 48k
• turn count → Fix auth middleware (34t)
• line count

or maybe on the left!

Ideal format would be configurable via a setting like Tab title size indicator: none | percent | tokens | turns, but even a single hardcoded metric (like % context used) would be a big improvement.

Alternative Solutions

I've also tried relying on the task summaries alone, but when working on related tasks they're too similar to differentiate at a glance.

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

1. I have 3 terminal tabs open, each running Claude Code on the same repo
2. Tab 1: fixing an auth bug (early stage, ~10% context)
3. Tab 2: fixing a related auth bug (deep into it, ~65% context)
4. Tab 3: refactoring auth middleware (nearly done, ~90% context)
5. All three tabs show similar summaries like "Fix auth middleware" or "Debug auth flow"
6. I copy a code snippet and switch tabs — I pick the wrong one and paste into the wrong session
7. With a size indicator, the tabs would look like Fix auth middleware [10%], Debug auth flow [65%], Refactor auth [90%] — instantly distinguishable

Additional Context

This would also serve as a passive context-limit awareness tool — you'd notice a tab approaching 100% without needing to check explicitly.