[Feature]: Show the context percentage on the meter, not only in its popover

[robertnisipeanu]

What

The context meter in the composer footer encodes usage as an arc only. Reading the actual number means hovering or clicking to open the popover. For people who watch context all day, that is a hover for a value that could just be on screen.

Proposal

Render the percentage on the meter itself. Two placements, both shown against the real component at 68%:

Option A — under the ring. Keeps the ring at its current diameter and stays legible at 9px.

Option B — inside the ring. Denser, but the ring has to grow and the text lands at ~7.5px, which is tight.

No preference from me. A is the safer default; B is there so the trade-off is visible.

Notes

apps/web/src/components/chat/ContextWindowMeter.tsx already computes the value — formatPercentage runs on every render and the result is already in the trigger aria-label. Today it is only rendered inside PopoverPopup.

Screenshots are the real component with the two variants patched in, not a drawing.

This was originally filed as issue #7651 while the repository Discussions/Ideas area was unavailable. Reposting it here now that Ideas is available, following the maintainer guidance on that issue. The proposed implementation remains in PR #7681.