Formatter prints "80.0%" and "$10000" when rounding crosses a precision boundary #417

Problem

TokenFormatter.percent and TokenFormatter.costCompact pick their output precision from the raw value and only then round. When rounding crosses a boundary, the result contradicts the branch:

percent checks value == value.rounded(), so any non-integer goes through %.1f, even when it rounds to .0. costCompact checks usd < 100 / usd < 10_000 on the raw value, so values just below a cutoff print in the format of the next bucket.

Reachability

The inputs are arbitrary fractions in production:

• Cursor usedPercent is fractional, and remaining mode shows 100 − x (menu bar UsageStore limit parts, popover quota rows, floating pet, notifications).
• The usage recap delta is abs(delta) * 100.
• Costs come from per-token prices (UsageCost.text(compact:), menu bar cost).

So the menu bar can show 5h 80.0% next to 7d 88%, or $10000 where every other value above $10K is $10.0K.

Why the tests missed it

LocalUsageCacheTests.testFormatterEdges only uses values in the middle of each bucket (88, 88.35, 9.54, 311.4). None of them rounds across a boundary.

Fix

Format with the bucket's precision first, then decide the bucket from the formatted string.