Show real photos for people instead of scene art

Your avatar is your photo, picked from the device by tapping it on Home or
from a new Profile photo row in Settings, shrunk to 256 px and kept on the
phone (there is no upload endpoint yet). Group members show the photo the
server sends in a new `photo` field, everywhere avatars appear. Without a
photo, an initial on a neutral disc. Mock mode bundles free Unsplash
portraits for the sample people.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KhQh614DMeYoQEH9SoMRUw

frontend/lib/Grounded/designs/ProgressRing.dart

@@ -53,8 +53,8 @@ class ProgressRing extends StatelessWidget {
             ),
             child: Center(
               child: child ??
-                  text("${(clamped * 100).round()}%", size * 0.22,
-                      TextType.Bold,
+                  text(
+                      "${(clamped * 100).round()}%", size * 0.22, TextType.Bold,
                       color: colorPrimaryDark),
             ),
           );