fix(stats): remove day axis from breakdown groupBy to eliminate duplicate rows

Author: k1yt

webview-ui/src/components/dashboard/DashboardView.tsx

@@ -170,7 +170,7 @@ const DashboardView = memo(({ onDone }: DashboardViewProps) => {
 				to,
 				timezone,
 				groupBy: (
-					[currentGroupBy, "day"] as Array<
+					[currentGroupBy] as Array<
 						"day" | "week" | "month" | "provider" | "model" | "mode" | "status" | "source"
 					>
 				).filter((v, i, a) => a.indexOf(v) === i),

webview-ui/src/components/dashboard/__tests__/DashboardView.spec.tsx

@@ -303,7 +303,7 @@ describe("DashboardView", () => {
 			expect(statsMsg.requestId).toMatch(/^dashboard-/)
 			expect(statsMsg.usageStatsQuery.preset).toBe("today")
 			expect(statsMsg.usageStatsQuery.groupBy).toContain("model")
-			expect(statsMsg.usageStatsQuery.groupBy).toContain("day")
+			expect(statsMsg.usageStatsQuery.groupBy).not.toContain("day")
 
 			const sessionsCall = postMessageMock.mock.calls.find(
 				(c) => (c[0] as { type: string }).type === "getDashboardSessions",