Square every corner, enlarge the main surfaces and add a to-do list

Rounded rectangles and round controls are now square across the app; only
status dots, glows, the sun, rings and the breathing circle stay round.
Cards, rows, thumbnails, featured cards, category tiles, the standing card
and the nav are larger. Home gets a quick To-do list kept on the device
(TodoItem in InternalMemory), seeded with sample items in mock mode.

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

frontend/lib/Grounded/see/goal/GoalDetailState.dart

@@ -242,7 +242,7 @@ class GoalDetailState extends State<GoalDetail>
       padding: const EdgeInsets.fromLTRB(16, 14, 16, 14),
       decoration: BoxDecoration(
         color: colorWhite.withValues(alpha: 0.08),
-        borderRadius: BorderRadius.circular(16),
+        borderRadius: BorderRadius.zero,
       ),
       child: Column(
         mainAxisSize: MainAxisSize.min,
@@ -405,7 +405,7 @@ class GoalDetailState extends State<GoalDetail>
               width: 58,
               height: 58,
               child: ClipRRect(
-                borderRadius: BorderRadius.circular(16),
+                borderRadius: BorderRadius.zero,
                 child: SceneArt(
                   palette: scenePalette(routine.kind),
                   seed: sceneSeed(routine.title),
@@ -454,7 +454,6 @@ class GoalDetailState extends State<GoalDetail>
                   color: routine.kind == RoutineKind.MustDo
                       ? colorPrimaryDark
                       : tone,
-                  shape: BoxShape.circle,
                 ),
                 child: Icon(CupertinoIcons.play_fill,
                     size: 15, color: colorWhite),