[Feature Request] Show task completion percentage in the status line, not just elapsed time

Problem

During long-running tasks, the CLI status line only shows elapsed time (and token usage). There is no indication of how far along the task actually is.

On large multi-step jobs — bulk content migrations, retrofits across hundreds of files, sweeps over many directories — elapsed time alone is not informative. "4m 12s" tells me the task is still running, but not whether it is 10% done or 90% done, and therefore not whether I should wait, go do something else, or interrupt because it has gone off the rails.

Requested behavior

Show a completion percentage (or k/N step counter) in the status line alongside the elapsed timer, whenever the work has a knowable denominator.

Something like:

  Working… 4m12s · step 7/20 (35%) · 12.4k tokens

Why the data likely already exists

The harness already tracks a number of things that could supply a denominator, in rough order of usefulness:

1. Todo/checklist state — when the model has committed to an N-item plan, completed / total is a directly meaningful percentage.
2. Subagent fan-out — for /workflows and parallel agent batches, the number of spawned vs. finished agents is already known to the harness.
3. Plan-mode steps — an approved plan is an ordered list of steps with a known length.

Even a partial version would help: showing progress only when a todo list or a workflow is active, and falling back to the current timer-only display otherwise, would cover the cases where the wait is longest.

Notes

• This is about task progress, not context/compaction progress (see #13234, which was about compaction specifically).
• #31527 asked for estimated time-to-completion and was closed as a duplicate. A raw percentage / step counter is a weaker but much more reliable signal than an ETA — it does not require predicting step duration, so it may be worth treating separately from ETA.
• A secondary benefit: a percentage that stops advancing is a useful early warning that a task is stuck, which the elapsed timer cannot convey.

Environment

• Claude Code 2.1.233
• macOS (darwin 25.5.0), zsh