feat(web): avatar thumbnails with original preview, registration avatar, pure-JS crypto fallback for http [CI]

web/src/features/common/AvatarPreview.module.css

@@ -0,0 +1,25 @@
+.stage {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: var(--space-2);
+}
+
+.image {
+  display: block;
+  width: min(100%, 420px);
+  max-height: 60dvh;
+  border-radius: var(--radius-lg);
+  background: var(--surface-2);
+  object-fit: contain;
+}
+
+.blur {
+  image-rendering: auto;
+}
+
+.note {
+  margin: 0;
+  color: var(--text-dim);
+  font-size: 12px;
+}