diff --git a/frontend/README.md b/frontend/README.md
index 4455887..2f222a0 100644
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -45,10 +45,10 @@ npm run dev
 - ✅ Submitted confirmation page and .well-known DevTools route
 
 ### **What's Coming (Phase 3)**
-- 🚧 Notifications: Integrate bulk mark-read endpoint end-to-end with optimistic cache and retry/backoff (target `POST /api/notifications/read` with `{ ids: string[] }`).
-- 🚧 Performance polish: Add skeleton loaders for Analytics and Students pages during initial load/refetch.
-- 🚧 Testing: Extend Playwright for grading workspace edits/publish flow and notifications realtime badge; continue broadening a11y.
-- 🚧 Realtime: Wire assessment publish/update and queue changes; expand predicate-based cache invalidation and coverage.
+- 🚧 Testing: Extend a11y and additional UI smoke as new features land.
+- ✅ Notifications: Bulk mark-read endpoint integrated with optimistic cache + retry/backoff.
+- ✅ Realtime: Assessment publish/update and grading queue change events are wired to invalidate caches via predicate-based invalidation.
+- ✅ Performance polish: Skeleton loaders added for Analytics and Students pages during initial load/refetch.
   
 <!-- Recently Implemented section removed; details are now reflected in the Development Roadmap below. -->
 
@@ -157,6 +157,12 @@ frontend/
   - `NEXT_PUBLIC_AUTH_MODE=mock`
 - To run against a real API/gateway, set `NEXT_PUBLIC_AUTH_MODE=api` and configure `NEXT_PUBLIC_API_URL` or `NEXT_PUBLIC_GATEWAY_URL` accordingly. You may also remove or adjust route stubs in the specs.
 
+## 🔑 Admin Panel Usage (quick notes)
+
+- Admin routes are protected with a role guard; non-admin users are redirected to their dashboard.
+- When logged in as an admin, the global nav shows “Admin” and “Users” links; the current route is highlighted.
+- Admin pages are scaffolded under `/admin` with sections for Dashboard, Users, Settings, Audit, and Reports. Data wiring will be incrementally added as APIs land.
+
 ## �🏗️ Application Architecture
 
 ### **Single Page Application (SPA) Structure**
@@ -1164,10 +1170,9 @@ export function AssessmentForm({ assessment, onSubmit }: AssessmentFormProps) {
 - 📝 Documentation
 
 ### Next steps
-- Notifications: integrate bulk mark-read API end-to-end with optimistic cache + retry/backoff
-- Performance polish: add skeleton loaders for Analytics and Students pages during initial load/refetch
-- Testing: extend Playwright to cover grading workspace edits/publish flows and notifications realtime badge updates
-- Realtime: wire assessment publish/update and queue changes; expand predicate-based invalidation and coverage
+- Testing: keep expanding E2E/a11y as admin features are implemented
+- Admin: wire dashboard metrics, users table (pagination/search/sort/filters), settings save/load with validation + audit log, audit filters/search/export, and system monitoring tiles
+- Realtime: broaden event coverage as new admin/system events are introduced
 
 ---
 
diff --git a/frontend/TODO.md b/frontend/TODO.md
index 4c4a6a0..d08ce14 100644
--- a/frontend/TODO.md
+++ b/frontend/TODO.md
@@ -4,12 +4,12 @@ Derived from the Development Roadmap (active, pending items only).
 
 
 Nice-to-have (adjacent improvements)
-- [ ] Skeletons: Add lightweight skeleton loaders for Analytics and Students pages during initial load and refetch.
+- [x] Skeletons: Add lightweight skeleton loaders for Analytics and Students pages during initial load and refetch.
 
 Upcoming (Phase 3 carryover)
-- [ ] Notifications: Integrate bulk mark-read endpoint end-to-end with optimistic cache and retry/backoff.
-- [ ] Grading workspace E2E: Extend Playwright coverage for edit/publish flows and edge cases.
-- [ ] Realtime: Wire assessment publish/update and queue changes; expand predicate-based invalidation.
+- [x] Notifications: Integrate bulk mark-read endpoint end-to-end with optimistic cache and retry/backoff.
+- [x] Grading workspace E2E: Extend Playwright coverage for edit/publish flows and edge cases.
+- [x] Realtime: Wire assessment publish/update and queue changes; expand predicate-based invalidation.
 
 Phase 4: Admin Experience (actionable tasks)
 
@@ -52,8 +52,8 @@ System monitoring
 - [ ] A11y + unit tests
 
 Admin navigation & permissions
-- [ ] Guard admin routes; redirect non-admin users
-- [ ] Add Admin to nav and highlight current route
+- [x] Guard admin routes; redirect non-admin users
+- [x] Add Admin to nav and highlight current route
 - [ ] Role-based rendering of sensitive actions/components
 
 Docs & E2E
diff --git a/frontend/src/app/teacher/assessments/[assessmentId]/analytics/loading.tsx b/frontend/src/app/teacher/assessments/[assessmentId]/analytics/loading.tsx
new file mode 100644
index 0000000..1644a67
--- /dev/null
+++ b/frontend/src/app/teacher/assessments/[assessmentId]/analytics/loading.tsx
@@ -0,0 +1,46 @@
+import { Skeleton } from "@/components/ui/skeleton";
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="flex items-center justify-between">
+        <div className="space-y-2">
+          <div className="h-6 w-56"><Skeleton /></div>
+          <div className="h-4 w-80"><Skeleton /></div>
+        </div>
+        <div className="flex gap-2">
+          <div className="h-8 w-28"><Skeleton /></div>
+          <div className="h-8 w-28"><Skeleton /></div>
+          <div className="h-8 w-28"><Skeleton /></div>
+        </div>
+      </div>
+
+      <section className="grid gap-3 sm:grid-cols-2 lg:grid-cols-4">
+        {[1,2,3,4].map((i) => (
+          <div key={i} className="rounded-md border p-4 space-y-2">
+            <div className="h-3 w-24"><Skeleton /></div>
+            <div className="h-7 w-20"><Skeleton /></div>
+          </div>
+        ))}
+      </section>
+
+      <section className="space-y-3">
+        <div className="flex items-center justify-between">
+          <div className="h-5 w-40"><Skeleton /></div>
+          <div className="h-3 w-48"><Skeleton /></div>
+        </div>
+        <div className="rounded-md border p-3 space-y-2">
+          {[1,2,3,4].map((i) => (
+            <div key={i} className="grid grid-cols-5 gap-3 items-center">
+              <div className="h-4 w-48"><Skeleton /></div>
+              <div className="h-3 w-24"><Skeleton /></div>
+              <div className="h-3 w-24"><Skeleton /></div>
+              <div className="h-3 w-16"><Skeleton /></div>
+              <div className="h-3 w-12 justify-self-end"><Skeleton /></div>
+            </div>
+          ))}
+        </div>
+      </section>
+    </div>
+  );
+}
diff --git a/frontend/src/app/teacher/grading/[submissionId]/page.tsx b/frontend/src/app/teacher/grading/[submissionId]/page.tsx
index 145a1ea..788e03e 100644
--- a/frontend/src/app/teacher/grading/[submissionId]/page.tsx
+++ b/frontend/src/app/teacher/grading/[submissionId]/page.tsx
@@ -30,7 +30,10 @@ export default function RubricPage() {
     mutationFn: updateQuestion,
     onSuccess: () => {
       qc.invalidateQueries({ queryKey: ['grade', submissionId] });
-    }
+    },
+    onError: () => {
+      error('Failed to save question grade. Please check your input and try again.');
+    },
   });
 
   const publishMutation = useMutation({
diff --git a/frontend/src/components/layout/header.tsx b/frontend/src/components/layout/header.tsx
index e896185..f64d696 100644
--- a/frontend/src/components/layout/header.tsx
+++ b/frontend/src/components/layout/header.tsx
@@ -22,6 +22,11 @@ export function Header() {
   // Hide header during assessment taking for distraction-free mode
   if (pathname?.startsWith("/student/assessment/")) return null;
 
+  const linkCls = (href: string) => {
+    const active = pathname === href || (href !== '/' && pathname?.startsWith(href + '/'));
+    return `hover:underline ${active ? 'font-medium text-foreground' : ''}`.trim();
+  };
+
   return (
     <header className="sticky top-0 z-40 w-full border-b bg-background/80 backdrop-blur">
       <div className="container flex h-14 items-center justify-between">
@@ -45,10 +50,19 @@ export function Header() {
           <nav className="hidden lg:flex items-center gap-4 text-sm text-muted">
             {hydrated && role && (
               <>
-                <Link href={("/" + role) as unknown as Route}>Dashboard</Link>
-                {role === "student" && <Link href={("/student/assessments" as Route)}>Assessments</Link>}
-                {role === "teacher" && <Link href={("/teacher/assessments" as Route)}>Assessments</Link>}
-                {role === "admin" && <Link href={("/admin/users" as Route)}>Users</Link>}
+                <Link className={linkCls("/" + role)} href={("/" + role) as unknown as Route} aria-current={pathname === ("/" + role) ? 'page' : undefined}>Dashboard</Link>
+                {role === "student" && (
+                  <Link className={linkCls("/student/assessments")} href={("/student/assessments" as Route)} aria-current={pathname?.startsWith("/student/assessments") ? 'page' : undefined}>Assessments</Link>
+                )}
+                {role === "teacher" && (
+                  <Link className={linkCls("/teacher/assessments")} href={("/teacher/assessments" as Route)} aria-current={pathname?.startsWith("/teacher/assessments") ? 'page' : undefined}>Assessments</Link>
+                )}
+                {role === "admin" && (
+                  <>
+                    <Link className={linkCls("/admin")} href={("/admin" as Route)} aria-current={pathname === "/admin" ? 'page' : undefined}>Admin</Link>
+                    <Link className={linkCls("/admin/users")} href={("/admin/users" as Route)} aria-current={pathname?.startsWith("/admin/users") ? 'page' : undefined}>Users</Link>
+                  </>
+                )}
               </>
             )}
           </nav>
@@ -74,10 +88,15 @@ export function Header() {
             )}
             {hydrated && role && (
               <>
-                <Link href={("/" + role) as unknown as Route} onClick={() => setOpen(false)}>Dashboard</Link>
-                {role === "student" && <Link href={("/student/assessments" as Route)} onClick={() => setOpen(false)}>Assessments</Link>}
-                {role === "teacher" && <Link href={("/teacher/assessments" as Route)} onClick={() => setOpen(false)}>Assessments</Link>}
-                {role === "admin" && <Link href={("/admin/users" as Route)} onClick={() => setOpen(false)}>Users</Link>}
+                <Link href={("/" + role) as unknown as Route} onClick={() => setOpen(false)} aria-current={pathname === ("/" + role) ? 'page' : undefined}>Dashboard</Link>
+                {role === "student" && <Link href={("/student/assessments" as Route)} onClick={() => setOpen(false)} aria-current={pathname?.startsWith("/student/assessments") ? 'page' : undefined}>Assessments</Link>}
+                {role === "teacher" && <Link href={("/teacher/assessments" as Route)} onClick={() => setOpen(false)} aria-current={pathname?.startsWith("/teacher/assessments") ? 'page' : undefined}>Assessments</Link>}
+                {role === "admin" && (
+                  <>
+                    <Link href={("/admin" as Route)} onClick={() => setOpen(false)} aria-current={pathname === "/admin" ? 'page' : undefined}>Admin</Link>
+                    <Link href={("/admin/users" as Route)} onClick={() => setOpen(false)} aria-current={pathname?.startsWith("/admin/users") ? 'page' : undefined}>Users</Link>
+                  </>
+                )}
                 <button className="text-left" onClick={() => { logout(); setOpen(false); }}>Logout</button>
               </>
             )}
diff --git a/frontend/src/tests/hooks/notifications-bulk.test.tsx b/frontend/src/tests/hooks/notifications-bulk.test.tsx
new file mode 100644
index 0000000..484c542
--- /dev/null
+++ b/frontend/src/tests/hooks/notifications-bulk.test.tsx
@@ -0,0 +1,88 @@
+import React from 'react';
+import { render, screen, fireEvent, waitFor } from '@testing-library/react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import * as Api from '@/lib/api';
+import { useBulkMarkNotificationsRead, applyNotificationsReadPatch } from '@/hooks/useNotifications';
+
+jest.useFakeTimers();
+
+function setupClient() {
+  const qc = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+  return qc;
+}
+
+function TestHarness({ ids }: { ids: string[] }) {
+  const mutate = useBulkMarkNotificationsRead();
+  return (
+    <button onClick={() => mutate.mutateAsync(ids)} data-testid="run" />
+  );
+}
+
+describe('notifications bulk mark-read', () => {
+  test('optimistically marks read and retries with backoff then succeeds', async () => {
+    const qc = setupClient();
+
+    // prime cache with unread items
+    const initial = [
+      { id: 'n1', title: 't1', createdAt: new Date().toISOString(), read: false },
+      { id: 'n2', title: 't2', createdAt: new Date().toISOString(), read: false },
+    ];
+    qc.setQueryData(['notifications', 50], initial);
+
+    // mock API: fail twice, then succeed
+    const bulkSpy = jest.spyOn(Api.NotificationsApi, 'bulkMarkRead')
+      .mockRejectedValueOnce(new Error('fail-1'))
+      .mockRejectedValueOnce(new Error('fail-2'))
+      .mockResolvedValue({ success: true });
+
+    const ids = ['n1', 'n2'];
+
+    render(
+      <QueryClientProvider client={qc}>
+        <TestHarness ids={ids} />
+      </QueryClientProvider>
+    );
+
+    fireEvent.click(screen.getByTestId('run'));
+
+    // optimistic patch applied (may be async due to react-query batching)
+    await waitFor(() => {
+      const afterOptimistic = qc.getQueryData(['notifications', 50]) as any[];
+      expect(afterOptimistic && afterOptimistic.every((n) => n.read === true)).toBe(true);
+    });
+
+    // advance timers for retries: delays ~200ms, 400ms (cap < 1500 in hook)
+    await Promise.resolve();
+    jest.advanceTimersByTime(250);
+    await Promise.resolve();
+    jest.advanceTimersByTime(450);
+
+    await waitFor(() => expect(bulkSpy).toHaveBeenCalledTimes(3));
+
+    // final state remains read
+    const final = qc.getQueryData(['notifications', 50]) as any[];
+    expect(final.every((n) => n.read === true)).toBe(true);
+  });
+
+  test('applyNotificationsReadPatch handles arrays and nested shapes', () => {
+    const ids = new Set(['a', 'b']);
+    const arr = [
+      { id: 'a', read: false },
+      { id: 'x', read: false },
+    ];
+    const res1 = applyNotificationsReadPatch(arr, ids) as any[];
+    expect(res1[0].read).toBe(true);
+    expect(res1[1].read).toBe(false);
+
+    const pages = {
+      pages: [
+        { items: [{ id: 'b', read: false }], notifications: [{ id: 'z', read: false }] },
+        { data: { notifications: [{ id: 'a', read: false }] } },
+      ],
+    } as any;
+    const res2 = applyNotificationsReadPatch(pages, ids) as any;
+    expect(res2.pages[0].items[0].read).toBe(true);
+    expect(res2.pages[0].notifications[0].read).toBe(false);
+    expect(res2.pages[1].data.notifications[0].read).toBe(true);
+  });
+});
diff --git a/frontend/tests/e2e/grading-workspace-edge-cases.spec.ts b/frontend/tests/e2e/grading-workspace-edge-cases.spec.ts
new file mode 100644
index 0000000..f5a2b39
--- /dev/null
+++ b/frontend/tests/e2e/grading-workspace-edge-cases.spec.ts
@@ -0,0 +1,91 @@
+import { test, expect } from "@playwright/test";
+
+// Covers validation/failure scenarios in grading workspace: save error and publish error
+
+test.describe("Manual grading workspace edge cases", () => {
+  test.beforeEach(async ({ page, baseURL }) => {
+    await page.addInitScript(() => {
+      localStorage.setItem("auth_token", "dummy-token");
+      localStorage.setItem("auth_role", "teacher");
+    });
+
+    await page.route("**/api/auth/me", async (route) => {
+      return route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({ data: { userId: "t1", name: "Teacher Test", role: "teacher" } }),
+      });
+    });
+
+    // Provide base grading data
+    await page.route("**/api/grade/submission/**", async (route) => {
+      if (route.request().method() === "GET") {
+        const url = new URL(route.request().url());
+        const submissionId = url.pathname.split("/").pop() ?? "SUB-200";
+        await route.fulfill({
+          status: 200,
+          contentType: "application/json",
+          body: JSON.stringify({
+            data: {
+              submissionId,
+              totalScore: 10,
+              maxScore: 10,
+              percentage: 100,
+              questionGrades: [
+                { questionId: "Q1", maxPoints: 10, pointsEarned: 10, feedback: "" },
+              ],
+            },
+          }),
+        });
+        return;
+      }
+      if (route.request().method() === "PUT") {
+        // Simulate validation failure if points > max
+        const body = route.request().postDataJSON() as any;
+        if (typeof body?.pointsEarned === 'number' && body.pointsEarned > 10) {
+          await route.fulfill({ status: 400, contentType: 'application/json', body: JSON.stringify({ success: false, error: 'Invalid points' }) });
+          return;
+        }
+        await route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify({ success: true }) });
+        return;
+      }
+      await route.continue();
+    });
+
+    // Publish failure endpoint
+    await page.route("**/grade/submission/**/publish", async (route) => {
+      await route.fulfill({ status: 500, contentType: 'application/json', body: JSON.stringify({ success: false }) });
+    });
+
+    await page.goto(`${baseURL!}/teacher`);
+  });
+
+  test("shows error toast on invalid save and prevents navigation", async ({ page, baseURL }) => {
+    const submissionId = "SUB-200";
+    await page.goto(`${baseURL!}/teacher/grading/${submissionId}`);
+
+    await expect(page.getByRole("heading", { name: /manual grading/i })).toBeVisible();
+
+    const pointsInput = page.locator('#points-Q1');
+    await pointsInput.fill('12');
+
+    const saveButton = pointsInput.locator('xpath=ancestor::form').getByRole('button', { name: /save/i });
+    await saveButton.click();
+
+    await expect(page.getByRole('status').filter({ hasText: /failed to save question grade/i })).toBeVisible();
+    // Still on the same page
+    await expect(page).toHaveURL(/\/teacher\/grading\/SUB-200$/);
+  });
+
+  test("shows error toast on publish failure and stays in workspace", async ({ page, baseURL }) => {
+    const submissionId = "SUB-200";
+    await page.goto(`${baseURL!}/teacher/grading/${submissionId}`);
+
+    const publishReq = page.waitForRequest((r) => r.method() === 'POST' && r.url().includes(`/grade/submission/${submissionId}/publish`));
+    await page.getByRole('button', { name: /publish/i }).click();
+    await publishReq;
+
+    await expect(page.getByRole('status').filter({ hasText: /failed to publish submission/i })).toBeVisible();
+    await expect(page).toHaveURL(/\/teacher\/grading\/SUB-200$/);
+  });
+});