fix(panel): active tab/route highlight (pickTab + sidebar footer exact match) (#520)

* feat(panel): add pickTab helper for validated URL tab params

* fix(panel): validate kanban view + KB tab params via pickTab

The bare `as T || default` cast only guarded null — a typo/invalid value
(?view=deev, ?tab=foo) passed through as an out-of-set TabValue, blanking the
active tab highlight and the content pane. pickTab validates against the
known set and falls back to the default on null/empty/invalid.

* fix(panel): highlight active sidebar footer link (exact match)

SidebarFooter had no isActive branch (SidebarNav does), so footer links
never highlighted. Added with EXACT match (pathname === href) — not
startsWith — so /settings does not also highlight on /settings/ai-providers.
Main nav keeps startsWith (longer hrefs need prefix matching); the two
intentionally differ.

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

panel/src/app/(dashboard)/kanban/page.tsx

@@ -10,16 +10,18 @@ import {
 } from "@/components/kanban";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { Skeleton } from "@/components/ui/skeleton";
+import { pickTab } from "@/lib/tabs";
 import { Code, TestTube, GitPullRequest, ClipboardList } from "lucide-react";
 
 type KanbanView = "dev" | "qa" | "pr-review" | "pm";
+const KANBAN_VIEWS = ["dev", "qa", "pr-review", "pm"] as const satisfies readonly KanbanView[];
 
 function KanbanPageContent() {
   const router = useRouter();
   const searchParams = useSearchParams();
 
-  // Read view from URL params, default to "dev"
+  // Read view from URL params; fall back to "dev" on null/empty/invalid.
-  const view = (searchParams.get("view") as KanbanView) || "dev";
+  const view: KanbanView = pickTab(searchParams.get("view"), KANBAN_VIEWS, "dev");
 
   const handleViewChange = (newView: string) => {
     if (newView === "dev") {

panel/src/components/knowledge-base/knowledge-base-browser.tsx

@@ -49,6 +49,7 @@ import { Skeleton } from "@/components/ui/skeleton";
 import { toast } from "sonner";
 import { formatDistanceToNow } from "date-fns";
 import { getErrorMessage } from "@/lib/api/client";
+import { pickTab } from "@/lib/tabs";
 import { usePageRefresh } from "@/hooks";
 
 // Components
@@ -62,7 +63,8 @@ import { MentorChat } from "./mentor-chat";
 import { KBCategoryNav } from "./kb-category-nav";
 import { KBCategoryView } from "./kb-category-view";
 
-type TabValue = "search" | "ask" | "mentor" | "browse" | "admin";
+const TAB_VALUES = ["search", "ask", "mentor", "browse", "admin"] as const;
+type TabValue = (typeof TAB_VALUES)[number];
 
 const INDEX_LABELS: Record<KBIndexType, string> = {
   [KBIndexType.DOCUMENTATION]: "Documentation",
@@ -95,8 +97,8 @@ function KnowledgeBaseBrowserContent() {
   const router = useRouter();
   const searchParams = useSearchParams();
 
-  // Read state from URL params
+  // Read state from URL params; fall back to "search" on null/empty/invalid.
-  const activeTab = (searchParams.get("tab") as TabValue) || "search";
+  const activeTab: TabValue = pickTab(searchParams.get("tab"), TAB_VALUES, "search");
   const searchQuery = searchParams.get("q") || "";
   const filtersParam = searchParams.get("filters");
   const searchFilters: KBIndexType[] = filtersParam

panel/src/components/layout/__tests__/sidebar-footer-active.test.tsx

@@ -0,0 +1,35 @@
+import { describe, expect, it, vi, beforeEach } from "vitest";
+import { render } from "@testing-library/react";
+
+// Mutable pathname shared with the hoisted mock factory.
+const { pathnameMock } = vi.hoisted(() => ({ pathnameMock: vi.fn() }));
+vi.mock("next/navigation", () => ({ usePathname: () => pathnameMock() }));
+
+import { SidebarFooter } from "../sidebar";
+
+function linkFor(container: HTMLElement, href: string) {
+  return container.querySelector<HTMLAnchorElement>(`a[href="${href}"]`);
+}
+
+describe("SidebarFooter active state (exact match)", () => {
+  beforeEach(() => pathnameMock.mockReset());
+
+  it("highlights only the matching footer link on /settings", () => {
+    pathnameMock.mockReturnValue("/settings");
+    const { container } = render(<SidebarFooter />);
+    expect(linkFor(container, "/settings")?.className).toMatch(/bg-primary/);
+    expect(linkFor(container, "/settings/ai-providers")?.className).not.toMatch(
+      /bg-primary/,
+    );
+    expect(linkFor(container, "/business")?.className).not.toMatch(/bg-primary/);
+  });
+
+  it("does not double-highlight /settings when on /settings/ai-providers", () => {
+    pathnameMock.mockReturnValue("/settings/ai-providers");
+    const { container } = render(<SidebarFooter />);
+    expect(linkFor(container, "/settings/ai-providers")?.className).toMatch(
+      /bg-primary/,
+    );
+    expect(linkFor(container, "/settings")?.className).not.toMatch(/bg-primary/);
+  });
+});

panel/src/components/layout/sidebar.tsx

@@ -119,18 +119,24 @@ export function SidebarFooter({
   collapsed?: boolean;
   onNavigate?: () => void;
 }) {
+  const pathname = usePathname();
   // No Separator here: both wrappers (desktop aside + mobile Sheet) already
   // draw a border-t, and a second line reads as a rendering glitch.
   return (
     <div className="space-y-1">
       {footerItems.map((item) => {
+        // Exact match: /settings must not also highlight on /settings/ai-providers.
+        const isActive = pathname === item.href;
         const link = (
           <Link
             prefetch={false}
             href={item.href}
             onClick={onNavigate}
             className={cn(
-              "flex items-center gap-3 rounded-lg px-3 py-2 text-sm font-medium text-muted-foreground hover:bg-muted hover:text-foreground transition-colors",
+              "flex items-center gap-3 rounded-lg px-3 py-2 text-sm font-medium transition-colors",
+              isActive
+                ? "bg-primary text-primary-foreground"
+                : "text-muted-foreground hover:bg-muted hover:text-foreground",
               collapsed && "justify-center px-2",
             )}
           >

panel/src/lib/__tests__/tabs.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from "vitest";
+import { pickTab } from "@/lib/tabs";
+
+const VIEWS = ["dev", "qa", "pr-review", "pm"] as const;
+
+describe("pickTab", () => {
+  it("returns the raw value when it is in the valid set", () => {
+    expect(pickTab("qa", VIEWS, "dev")).toBe("qa");
+  });
+
+  it("falls back when raw is null", () => {
+    expect(pickTab(null, VIEWS, "dev")).toBe("dev");
+  });
+
+  it("falls back when raw is an invalid/typo value", () => {
+    expect(pickTab("deev", VIEWS, "dev")).toBe("dev");
+    expect(pickTab("foo", VIEWS, "dev")).toBe("dev");
+  });
+
+  it("falls back when raw is the empty string", () => {
+    expect(pickTab("", VIEWS, "dev")).toBe("dev");
+  });
+});

panel/src/lib/tabs.ts

@@ -0,0 +1,13 @@
+/**
+ * Validate a URL search-param tab/view value against a known set, falling
+ * back to a default when it is null, empty, or not in the set. Replaces the
+ * bare `as T || default` cast that only guards null and lets a typo value
+ * blank the active tab + content pane.
+ */
+export function pickTab<T extends string>(
+  raw: string | null,
+  valid: readonly T[],
+  fallback: T,
+): T {
+  return valid.includes(raw as T) ? (raw as T) : fallback;
+}