diff --git a/docs/reports/coverage-2026-08-23.md b/docs/reports/coverage-2026-08-23.md
new file mode 100644
index 0000000..4ff67f2
--- /dev/null
+++ b/docs/reports/coverage-2026-08-23.md
@@ -0,0 +1,55 @@
+# Coverage Report — 2026-08-23
+
+## Summary
+
+| Metric | Before | After |
+|--------|--------|-------|
+| Statements | 89.56% | 93.47% |
+| Branches | 77.41% | 81.60% |
+| Functions | 79.41% | 97.05% |
+| Lines | 92.49% | 95.08% |
+
+Total tests: 265 → 277 (+12 new tests).
+
+## Week-over-Week (vs 2026-06-21)
+
+| Metric | 2026-06-21 | 2026-08-23 | Change |
+|--------|-----------|-----------|--------|
+| Statements | 89.56% | 93.47% | +3.91% |
+| Branches | 77.41% | 81.60% | +4.19% |
+| Functions | 79.41% | 97.05% | +17.64% |
+| Lines | 92.49% | 95.08% | +2.59% |
+| Test count | 265 | 277 | +12 |
+
+Files with improved coverage:
+- `lib/activity.js` — 77.58% → 97.41% statements, 29.16% → 100% functions
+- `lib/notifications.js` — 87.27% → 100% statements (all metrics now 100%)
+- `lib/reactions.js` — 90.47% → 95.23% statements, 81.25% → 89.58% branches
+
+## Files Changed (last 7 days)
+
+No `lib/` files were modified in the last 7 days. Fell back to lowest-coverage files overall.
+
+## New Tests Written
+
+- `tests/unit/lib/activity.test.js` — 5 new tests, covers: getGroupActivity (happy path with profiles + reactions, missing profile fallback), getAllActivity (test-data filtering, profile + reaction attachment), getGroupStats (full stats + leaderboard computation)
+- `tests/unit/lib/notifications.test.js` — 4 new tests, covers: getNotifications (happy path, null data, DB error, custom limit)
+- `tests/unit/lib/reactions.test.js` — 3 new tests, covers: toggleReaction (non-PGRST116 error), getBatchReactions (unknown activity_id in data, auth failure graceful handling)
+
+## Skipped (out of scope)
+
+- `lib/FocusContext.js`, `lib/NotificationContext.js`, `lib/KeyboardShortcutsContext.js` — React context providers
+- `lib/animations.js` — pure animation data presets, no logic to test
+- `lib/supabase/*` — Supabase client configuration
+- `lib/confetti.js` — relies on DOM APIs; browser-only with no testable pure logic
+- `lib/sounds.js` — relies on Web Audio API; browser-only with no testable pure logic
+- `lib/email.js` — core logic in non-exported functions; only export requires real Resend client
+- `lib/useKeyboardShortcuts.js`, `lib/useModalScrollLock.js` — React hooks, out of scope
+- `lib/streaks-advanced.js` — remaining uncovered lines (247, 355-356, 377) are in dynamic import / notification paths that require integration-level mocking; coverage at 84.12% statements
+
+## Notes
+
+- The biggest win was `activity.js` functions coverage jumping from 29.16% to 100%. The `getGroupActivity`, `getAllActivity`, and `getGroupStats` functions required a multi-table mock (separate builders per `from(table)` call) to test their happy paths — a `createActivityTableMock` helper was added to the test file for this purpose.
+- `notifications.js` reached 100% across all metrics by adding the previously-missing `getNotifications` tests.
+- `reactions.js` branch coverage improved by testing the `getBatchReactions` edge case where returned data includes an `activity_id` not in the original query array (line 70), and the `toggleReaction` non-PGRST116 error path (line 103).
+- `streaks-advanced.js` remains at 84.12% statements. The uncovered lines are in dynamic `import()` blocks for notifications inside `awardStreakFreeze` and `checkStreakMilestone` — testing those would require mocking ES module dynamic imports, which adds complexity disproportionate to the coverage gain.
diff --git a/tests/unit/lib/activity.test.js b/tests/unit/lib/activity.test.js
index b55c38b..40087d4 100644
--- a/tests/unit/lib/activity.test.js
+++ b/tests/unit/lib/activity.test.js
@@ -319,4 +319,204 @@ describe('getGroupStats', () => {
     expect(result.leaderboard).toEqual([]);
     expect(result.error).toBeNull();
   });
+
+  it('computes stats and leaderboard from real data', async () => {
+    const { supabase, builders } = createActivityTableMock(['group_members', 'activity_log', 'tasks', 'profiles']);
+
+    builders['group_members'].resolveWith({
+      data: [{ user_id: 'u1' }, { user_id: 'u2' }],
+      error: null,
+    });
+
+    builders['activity_log'].resolveWith({
+      data: [
+        { user_id: 'u1' },
+        { user_id: 'u1' },
+        { user_id: 'u2' },
+      ],
+      error: null,
+    });
+
+    builders['tasks'].resolveWith({
+      data: [
+        { id: 't1', status: 'done', owner_id: 'u1' },
+        { id: 't2', status: 'done', owner_id: 'u2' },
+        { id: 't3', status: 'in_progress', owner_id: 'u1' },
+        { id: 't4', status: 'todo', owner_id: 'u2' },
+      ],
+      error: null,
+    });
+
+    builders['profiles'].resolveWith({
+      data: [
+        { id: 'u1', full_name: 'Alice', avatar_url: null },
+        { id: 'u2', full_name: 'Bob', avatar_url: null },
+      ],
+      error: null,
+    });
+
+    const result = await getGroupStats(supabase, 'group-1');
+
+    expect(result.error).toBeNull();
+    expect(result.stats).toEqual({
+      totalTasks: 4,
+      completedTasks: 2,
+      completionRate: 50,
+      activeTasks: 2,
+    });
+    expect(result.leaderboard).toHaveLength(2);
+    expect(result.leaderboard[0].full_name).toBe('Alice');
+    expect(result.leaderboard[0].completions).toBe(2);
+    expect(result.leaderboard[1].full_name).toBe('Bob');
+    expect(result.leaderboard[1].completions).toBe(1);
+  });
+});
+
+/**
+ * Multi-table mock: each from(table) call returns a distinct builder so
+ * sequential queries against different tables resolve independently.
+ */
+function createActivityTableMock(tables) {
+  function makeBuilder() {
+    const chainMethods = [
+      'select', 'eq', 'neq', 'in', 'not', 'gte', 'order', 'range',
+      'single', 'maybeSingle', 'insert', 'update', 'delete', 'limit',
+    ];
+    const b = {
+      resolveWith(value) {
+        b.then = (resolve) => resolve(value);
+      },
+    };
+    chainMethods.forEach((m) => {
+      b[m] = vi.fn(() => b);
+    });
+    b.resolveWith({ data: null, error: null });
+    return b;
+  }
+
+  const builders = {};
+  (tables || []).forEach((t) => { builders[t] = makeBuilder(); });
+
+  const supabase = {
+    from: vi.fn((table) => {
+      if (!builders[table]) builders[table] = makeBuilder();
+      return builders[table];
+    }),
+    rpc: vi.fn().mockResolvedValue({ data: null, error: null }),
+    auth: {
+      getUser: vi.fn().mockResolvedValue({
+        data: { user: { id: 'test-user-id' } },
+        error: null,
+      }),
+    },
+  };
+  return { supabase, builders };
+}
+
+describe('getGroupActivity — happy path', () => {
+  it('attaches user profiles and reactions to activities', async () => {
+    const { supabase, builders } = createActivityTableMock(['activity_log', 'profiles', 'activity_reactions']);
+
+    builders['activity_log'].resolveWith({
+      data: [
+        { id: 'act-1', user_id: 'u1', action: 'task_completed', group_id: 'g1', metadata: {} },
+        { id: 'act-2', user_id: 'u2', action: 'pact_created', group_id: 'g1', metadata: {} },
+      ],
+      error: null,
+    });
+
+    builders['profiles'].resolveWith({
+      data: [
+        { id: 'u1', full_name: 'Alice', avatar_url: 'https://example.com/a.png' },
+        { id: 'u2', full_name: 'Bob', avatar_url: null },
+      ],
+      error: null,
+    });
+
+    builders['activity_reactions'].resolveWith({
+      data: [
+        { activity_id: 'act-1', user_id: 'test-user-id', reaction: 'fire' },
+      ],
+      error: null,
+    });
+
+    const result = await getGroupActivity(supabase, 'g1');
+
+    expect(result.error).toBeNull();
+    expect(result.data).toHaveLength(2);
+    expect(result.data[0].user.full_name).toBe('Alice');
+    expect(result.data[0].reactions.counts).toEqual({ fire: 1 });
+    expect(result.data[0].reactions.userReactions).toEqual(['fire']);
+    expect(result.data[1].user.full_name).toBe('Bob');
+    expect(result.data[1].reactions.total).toBe(0);
+  });
+
+  it('falls back to Unknown for missing profiles', async () => {
+    const { supabase, builders } = createActivityTableMock(['activity_log', 'profiles', 'activity_reactions']);
+
+    builders['activity_log'].resolveWith({
+      data: [{ id: 'act-1', user_id: 'deleted-user', action: 'task_completed', group_id: 'g1', metadata: {} }],
+      error: null,
+    });
+
+    builders['profiles'].resolveWith({ data: [], error: null });
+    builders['activity_reactions'].resolveWith({ data: [], error: null });
+
+    const result = await getGroupActivity(supabase, 'g1');
+
+    expect(result.data[0].user.full_name).toBe('Unknown');
+    expect(result.data[0].user.avatar_url).toBeNull();
+  });
+});
+
+describe('getAllActivity — happy path', () => {
+  it('filters out test-data entries and respects the limit', async () => {
+    const { supabase, builders } = createActivityTableMock(['activity_log', 'profiles', 'activity_reactions']);
+
+    builders['activity_log'].resolveWith({
+      data: [
+        { id: 'a1', user_id: 'u1', action: 'pact_completed', metadata: { title: 'Study math' } },
+        { id: 'a2', user_id: 'u1', action: 'pact_created', metadata: { title: 'Bulk Test Pact' } },
+        { id: 'a3', user_id: 'u1', action: 'task_completed', metadata: { title: '[TEST] ignore me' } },
+        { id: 'a4', user_id: 'u1', action: 'pact_completed', metadata: { title: 'Read chapter 5' } },
+      ],
+      error: null,
+    });
+
+    builders['profiles'].resolveWith({
+      data: [{ id: 'u1', full_name: 'Alice', avatar_url: null }],
+      error: null,
+    });
+
+    builders['activity_reactions'].resolveWith({ data: [], error: null });
+
+    const result = await getAllActivity(supabase, 2);
+
+    expect(result.error).toBeNull();
+    const titles = result.data.map((a) => a.metadata.title);
+    expect(titles).not.toContain('Bulk Test Pact');
+    expect(titles).not.toContain('[TEST] ignore me');
+    expect(result.data.length).toBeLessThanOrEqual(2);
+  });
+
+  it('attaches user profiles and default reactions', async () => {
+    const { supabase, builders } = createActivityTableMock(['activity_log', 'profiles', 'activity_reactions']);
+
+    builders['activity_log'].resolveWith({
+      data: [{ id: 'a1', user_id: 'u1', action: 'pact_completed', metadata: { title: 'Run 5k' } }],
+      error: null,
+    });
+
+    builders['profiles'].resolveWith({
+      data: [{ id: 'u1', full_name: 'Alice', avatar_url: null }],
+      error: null,
+    });
+
+    builders['activity_reactions'].resolveWith({ data: [], error: null });
+
+    const result = await getAllActivity(supabase);
+
+    expect(result.data[0].user.full_name).toBe('Alice');
+    expect(result.data[0].reactions).toEqual({ counts: {}, userReactions: [], total: 0 });
+  });
 });
diff --git a/tests/unit/lib/notifications.test.js b/tests/unit/lib/notifications.test.js
index 41bbdff..8c8d0d0 100644
--- a/tests/unit/lib/notifications.test.js
+++ b/tests/unit/lib/notifications.test.js
@@ -2,6 +2,7 @@ import { describe, it, expect } from 'vitest';
 import {
   NOTIFICATION_TYPES,
   getNotificationIcon,
+  getNotifications,
   getUnreadCount,
   markAsRead,
   markAllAsRead,
@@ -9,6 +10,48 @@ import {
 } from '@/lib/notifications';
 import { createMockSupabase } from '../../setup/supabase-mock';
 
+describe('getNotifications', () => {
+  it('returns notifications on success', async () => {
+    const { supabase, builder } = createMockSupabase();
+    const rows = [
+      { id: 'n1', type: 'pact_reminder', title: 'Reminder', message: 'Due soon', is_read: false, created_at: '2024-06-15T12:00:00Z' },
+      { id: 'n2', type: 'streak_milestone', title: '7 days!', message: 'Keep going', is_read: true, created_at: '2024-06-14T12:00:00Z' },
+    ];
+    builder.mockReturnValue({ data: rows, error: null });
+
+    const result = await getNotifications(supabase);
+    expect(result.data).toEqual(rows);
+    expect(result.error).toBeNull();
+  });
+
+  it('returns empty array when data is null', async () => {
+    const { supabase, builder } = createMockSupabase();
+    builder.mockReturnValue({ data: null, error: null });
+
+    const result = await getNotifications(supabase);
+    expect(result.data).toEqual([]);
+    expect(result.error).toBeNull();
+  });
+
+  it('returns empty array and error on DB failure', async () => {
+    const { supabase, builder } = createMockSupabase();
+    builder.mockReturnValue({ data: null, error: { message: 'DB down' } });
+
+    const result = await getNotifications(supabase);
+    expect(result.data).toEqual([]);
+    expect(result.error).toBeTruthy();
+  });
+
+  it('respects a custom limit', async () => {
+    const { supabase, builder } = createMockSupabase();
+    builder.mockReturnValue({ data: [{ id: 'n1' }], error: null });
+
+    const result = await getNotifications(supabase, 5);
+    expect(result.data).toHaveLength(1);
+    expect(builder.limit).toHaveBeenCalledWith(5);
+  });
+});
+
 describe('NOTIFICATION_TYPES', () => {
   it('is an object with string values', () => {
     expect(typeof NOTIFICATION_TYPES).toBe('object');
diff --git a/tests/unit/lib/reactions.test.js b/tests/unit/lib/reactions.test.js
index 974c110..9d114e1 100644
--- a/tests/unit/lib/reactions.test.js
+++ b/tests/unit/lib/reactions.test.js
@@ -194,4 +194,46 @@ describe('toggleReaction', () => {
     expect(result.success).toBe(false);
     expect(result.error).toBeTruthy();
   });
+
+  it('throws on non-PGRST116 error from existence check', async () => {
+    const { supabase, builder } = createMockSupabase();
+    builder.mockReturnValue({ data: null, error: { code: 'INTERNAL', message: 'unexpected' } });
+
+    const result = await toggleReaction(supabase, 'a1', 'fire');
+    expect(result.success).toBe(false);
+    expect(result.error).toBeTruthy();
+  });
+});
+
+describe('getBatchReactions — edge cases', () => {
+  it('handles reactions for activity IDs not in the original array', async () => {
+    const { supabase, builder } = createMockSupabase();
+    builder.mockReturnValue({
+      data: [
+        { activity_id: 'a1', user_id: 'test-user-id', reaction: 'fire' },
+        { activity_id: 'unknown-id', user_id: 'test-user-id', reaction: 'clap' },
+      ],
+      error: null,
+    });
+
+    const result = await getBatchReactions(supabase, ['a1']);
+    expect(result.reactionsMap.a1.counts).toEqual({ fire: 1 });
+    expect(result.reactionsMap['unknown-id'].counts).toEqual({ clap: 1 });
+    expect(result.reactionsMap['unknown-id'].total).toBe(1);
+  });
+
+  it('handles auth failure gracefully (no userReactions tracked)', async () => {
+    const { supabase, builder } = createMockSupabase();
+    supabase.auth.getUser.mockResolvedValue({ data: null, error: { message: 'auth down' } });
+    builder.mockReturnValue({
+      data: [
+        { activity_id: 'a1', user_id: 'test-user-id', reaction: 'fire' },
+      ],
+      error: null,
+    });
+
+    const result = await getBatchReactions(supabase, ['a1']);
+    expect(result.reactionsMap.a1.counts).toEqual({ fire: 1 });
+    expect(result.reactionsMap.a1.userReactions).toEqual([]);
+  });
 });