fix(usage): compare the project with the same period it is shown against

The contribution note divided a project's usage over the period on screen
by the organisation's usage over the allowance window. Different windows,
so on Last 90 days with a project chosen it could read as more than 100%
of the organisation.

It now takes the unfiltered total for the period being viewed. With no
project chosen the arguments match the query already running and RTK
serves both from one request, so the extra call only happens while a
filter is applied.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: talissoncosta

frontend/documentation/components/UsageDashboard.stories.tsx

@@ -100,11 +100,18 @@ const UsagePage: FC<HarnessProps> = ({
     scenarioFor(billingPeriod, !!empty, isFreePlan),
     share * scale,
   )
-  const organisationTotal = toUsageResponse(
+  const allowanceTotal = toUsageResponse(
     scenarioFor(allowanceWindow(basis), !!empty, isFreePlan),
     scale,
   ).totals.total
 
+  // The note needs the organisation over the period on screen, not over the
+  // allowance window, or a project can read as more than all of it.
+  const periodTotal = toUsageResponse(
+    scenarioFor(billingPeriod, !!empty, isFreePlan),
+    scale,
+  ).totals.total
+
   const { setDimension, ...breakdown } = useUsageBreakdown({ data: scoped })
 
   const scope = `${filtered ? project : 'All projects'} · ${periodLabel(
@@ -149,7 +156,7 @@ const UsagePage: FC<HarnessProps> = ({
       limit={limit}
       meterNote={
         filtered
-          ? contributionNote(project, scoped.totals.total, organisationTotal)
+          ? contributionNote(project, scoped.totals.total, periodTotal)
           : undefined
       }
       onRetry={() => {}}
@@ -159,7 +166,7 @@ const UsagePage: FC<HarnessProps> = ({
         billingPeriod,
         filtered ? 1 : undefined,
       )}
-      total={organisationTotal}
+      total={allowanceTotal}
     />
   )
 }

frontend/web/components/pages/usage/UsageDashboardPage.tsx

@@ -84,6 +84,17 @@ const UsageDashboardPage: FC<UsageDashboardPageProps> = ({
       { refetchOnFocus: false },
     )
 
+  // The note compares a project with the organisation over the same period, so
+  // it needs the unfiltered total for the period on screen, not the allowance
+  // one. With no project chosen the arguments match the query above and RTK
+  // serves both from one request.
+  const { data: periodData } = useGetOrganisationUsageQuery(
+    organisationId && organisation && selectedProjectId
+      ? { billing_period: billingPeriod, organisationId }
+      : skipToken,
+    { refetchOnFocus: false },
+  )
+
   const {
     data: subscriptionMeta,
     isLoading: loadingLimit,
@@ -122,7 +133,7 @@ const UsageDashboardPage: FC<UsageDashboardPageProps> = ({
           ? contributionNote(
               projectName,
               data?.totals?.total ?? 0,
-              organisationData?.totals?.total ?? 0,
+              periodData?.totals?.total ?? 0,
             )
           : undefined
       }

frontend/web/components/pages/usage/__tests__/utils.test.ts

@@ -62,6 +62,12 @@ describe('UsageDashboard utils', () => {
     it('has nothing to say when the organisation used nothing', () => {
       expect(contributionNote('Checkout', 0, 0)).toBeUndefined()
     })
+
+    it('never reports a project as more than all of the usage', () => {
+      expect(contributionNote('Checkout', 1000000, 1000000)).toBe(
+        'Checkout accounts for 100% of that usage.',
+      )
+    })
   })
 
   describe('planSectionCopy', () => {