feat(ui) : improve guide navigation, signup, and commissions

lib/guides/comparison.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from "vitest";
+import { comparisonDelta, comparisonReferenceNames } from "./comparison";
+
+describe("weapon comparison context", () => {
+  it("shows relative gains and losses, including decimals", () => {
+    expect(comparisonDelta("109")).toBe("+9% จากค่าฐาน");
+    expect(comparisonDelta("98.5")).toBe("-1.5% จากค่าฐาน");
+    expect(comparisonDelta("100")).toBe("เท่าค่าฐาน");
+  });
+  it("does not present missing or placeholder numbers as damage losses", () => {
+    for (const value of [null, "0", "invalid"]) expect(comparisonDelta(value)).toBeNull();
+  });
+  it("keeps team and personal reference rows separate", () => {
+    const rows = [
+      { weapon: { name: "Team reference" }, refinement: "5", overallPercent: "100", personalPercent: "110" },
+      { weapon: { name: "Personal reference" }, refinement: "1", overallPercent: "105", personalPercent: "100" },
+    ];
+    expect(comparisonReferenceNames(rows, "overallPercent")).toEqual(["Team reference R5"]);
+    expect(comparisonReferenceNames(rows, "personalPercent")).toEqual(["Personal reference R1"]);
+    expect(comparisonReferenceNames(rows.slice(0, 1), "personalPercent")).toEqual([]);
+  });
+});