fix: normalize percentage metric filter values for correct comparison

[ericokuma]

Summary

Fixes the metrics filter not functioning for percentage types (APP-779).

When a measure uses percentage format (format_preset: "percentage" or format_d3 with %), the underlying data is stored as a decimal (e.g., 0.8 for 80%). Previously, users entering "80" in the filter threshold would send 80 to the backend instead of 0.8, making the filter ineffective.

Changes

• measure-filter-entry.ts: Added isMeasurePercentFormat() utility that detects percentage-formatted measures by checking formatPreset === "percentage" or formatD3 containing %
• MeasureFilterForm.svelte: Converts between display values (×100) and raw values (÷100) for percentage measures. Shows a % suffix label next to the threshold input fields
• MeasureFilterBody.svelte: Displays filter chip values multiplied by 100 with % suffix for percentage measures (e.g., "< 80%" instead of "< 0.8")
• MeasureFilter.svelte: Passes the isPercent flag from MeasureFilterItem to both the form and body components
• measure-filters.ts (selectors), Filters.ts, filter-state.ts, filter-manager.ts: Set isPercent on MeasureFilterItem from the measure spec at all creation points (explore dashboards, canvas, scheduled reports)

How it works

The fix operates at the UI boundary level:

1. The MeasureFilterEntry stores raw decimal values (e.g., "0.8") — same as before
2. The form displays values multiplied by 100 (e.g., "80") and converts back (÷100) on submit
3. The filter chip displays values multiplied by 100 with "%" suffix
4. No changes to the core mapMeasureFilterToExpr/mapExprToMeasureFilter functions or URL/proto serialization — backward compatible

Closes APP-779

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

Linear Issue: APP-779