feat(examples): Add video-resource-server example

Demonstrates serving binary content (video) via MCP resources using the
base64 blob pattern:

1. Server fetches video from CDN
2. Returns as base64 blob via `videos://{id}` resource template
3. Widget fetches resource and plays in `<video>` element

Includes multiple video sizes for testing (1MB to 150MB).

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

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

examples/video-resource-server/src/mcp-app.css

@@ -0,0 +1,54 @@
+.main {
+  width: 100%;
+  max-width: 640px;
+}
+
+.loading {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: 2rem;
+  gap: 1rem;
+  color: #6b7280;
+}
+
+.spinner {
+  width: 48px;
+  height: 48px;
+  border: 4px solid #e5e7eb;
+  border-top-color: #3b82f6;
+  border-radius: 50%;
+  animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+  to { transform: rotate(360deg); }
+}
+
+.error {
+  padding: 1rem;
+  color: #dc2626;
+}
+
+.error-title {
+  font-weight: 600;
+  margin: 0 0 0.5rem 0;
+}
+
+.error p {
+  margin: 0;
+}
+
+.player video {
+  width: 100%;
+  max-height: 480px;
+  border-radius: 8px;
+  background-color: #000;
+}
+
+.video-info {
+  margin-top: 0.5rem;
+  font-size: 0.875rem;
+  color: #6b7280;
+}