Initial commit: watch-together phases 0-4 + presence hardening, internet-tested

apps/desktop/lib/src/widgets/member_avatar.dart

@@ -0,0 +1,65 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+
+class MemberAvatar extends StatelessWidget {
+  final String avatarBase64;
+  final String name;
+  final double size;
+
+  static final Map<String, MemoryImage> _images = {};
+
+  const MemberAvatar({
+    super.key,
+    required this.avatarBase64,
+    required this.name,
+    this.size = 40,
+  });
+
+  static MemoryImage? _providerFor(String raw) {
+    if (raw.isEmpty) return null;
+    var hit = _images[raw];
+    if (hit != null) return hit;
+    try {
+      hit = MemoryImage(base64Decode(raw));
+    } catch (_) {
+      return null;
+    }
+    if (_images.length > 64) _images.clear();
+    _images[raw] = hit;
+    return hit;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final image = _providerFor(avatarBase64);
+    final decoration = BoxDecoration(
+      shape: BoxShape.circle,
+    );
+    if (image != null) {
+      return Container(
+        decoration: decoration,
+        child: ClipOval(
+          child: Image(
+            image: ResizeImage(height: (size * MediaQuery.of(context).devicePixelRatio).round(), image),
+            width: size,
+            height: size,
+            fit: BoxFit.cover,
+            gaplessPlayback: true,
+            errorBuilder: (_, __, ___) => _fallback(),
+          ),
+        ),
+      );
+    }
+    return Container(decoration: decoration, child: _fallback());
+  }
+
+  Widget _fallback() => CircleAvatar(
+        radius: size / 2,
+        backgroundColor: Colors.grey.shade800,
+        child: Text(
+          name.isEmpty ? '?' : name[0].toUpperCase(),
+          style: TextStyle(fontSize: size * 0.4, color: Colors.white),
+        ),
+      );
+}