feat(client): add sync status indicator component

Add SyncStatusIndicator component to display current sync state in the
UI header. The component shows online/offline status, syncing progress,
pending changes count, and sync errors.

- Create SyncProvider context to wrap SyncManager for React components
- Add SyncStatusIndicator component with visual status indicators
- Integrate indicator into HomePage header
- Add comprehensive tests for SyncStatusIndicator and SyncProvider
- Update existing tests to include SyncProvider wrapper

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/client/App.test.tsx b/src/client/App.test.tsx
index c11eb88..8359e67 100644
--- a/src/client/App.test.tsx
+++ b/src/client/App.test.tsx
@@ -1,13 +1,14 @@
 /**
  * @vitest-environment jsdom
  */
+import "fake-indexeddb/auto";
 import { cleanup, render, screen } from "@testing-library/react";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { Router } from "wouter";
 import { memoryLocation } from "wouter/memory-location";
 import { App } from "./App";
 import { apiClient } from "./api/client";
-import { AuthProvider } from "./stores";
+import { AuthProvider, SyncProvider } from "./stores";
 
 vi.mock("./api/client", () => ({
 	apiClient: {
@@ -53,7 +54,9 @@ function renderWithRouter(path: string) {
 	return render(
 		<Router hook={hook}>
 			<AuthProvider>
-				<App />
+				<SyncProvider>
+					<App />
+				</SyncProvider>
 			</AuthProvider>
 		</Router>,
 	);