design: add bottom-nav badge scheme

src/app/components/navigation/role-nav.test.ts

@@ -0,0 +1,33 @@
+import { formatBadgeCount, getBadgeAriaLabel } from "./role-nav";
+
+describe("role-nav badge scheme", () => {
+  describe("formatBadgeCount", () => {
+    it("returns string representation of counts under 100", () => {
+      expect(formatBadgeCount(0)).toBe("0");
+      expect(formatBadgeCount(5)).toBe("5");
+      expect(formatBadgeCount(99)).toBe("99");
+    });
+
+    it("caps counts greater than 99 at '99+'", () => {
+      expect(formatBadgeCount(100)).toBe("99+");
+      expect(formatBadgeCount(1000)).toBe("99+");
+      expect(formatBadgeCount(9999)).toBe("99+");
+    });
+  });
+
+  describe("getBadgeAriaLabel", () => {
+    it("announces dot badge correctly", () => {
+      expect(getBadgeAriaLabel({ type: "dot" })).toBe("New updates available");
+    });
+
+    it("announces singular count correctly", () => {
+      expect(getBadgeAriaLabel({ type: "count", value: 1 })).toBe("1 new update");
+    });
+
+    it("announces plural counts correctly", () => {
+      expect(getBadgeAriaLabel({ type: "count", value: 5 })).toBe("5 new updates");
+      expect(getBadgeAriaLabel({ type: "count", value: 100 })).toBe("100 new updates");
+      expect(getBadgeAriaLabel({ type: "count", value: 9999 })).toBe("9999 new updates");
+    });
+  });
+});

src/app/components/navigation/role-nav.ts

@@ -22,6 +22,10 @@ export const ALL_ROLES: UserRole[] = ["supplier", "buyer", "admin"];
 
 // ─── Nav item shape ───────────────────────────────────────────────────────────
 
+export type NavBadge =
+  | { type: "dot" }
+  | { type: "count"; value: number };
+
 export interface NavItem {
   /** Route href */
   href: string;
@@ -35,6 +39,25 @@ export interface NavItem {
   icon: string;
   /** aria-label override for screen readers when label alone is ambiguous */
   ariaLabel?: string;
+  /** Optional badge indicator (dot or count) */
+  badge?: NavBadge;
+}
+
+/**
+ * Formats a badge count for visual display, capping at "99+".
+ */
+export function formatBadgeCount(value: number): string {
+  return value > 99 ? "99+" : value.toString();
+}
+
+/**
+ * Generates an accessible screen reader announcement for the badge.
+ */
+export function getBadgeAriaLabel(badge: NavBadge): string {
+  if (badge.type === "dot") {
+    return "New updates available";
+  }
+  return `${badge.value} new ${badge.value === 1 ? "update" : "updates"}`;
 }
 
 // ─── Shared primitives (common to every role) ─────────────────────────────────