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/routine/RoutineBuilderState.dart

@@ -402,7 +402,7 @@ class RoutineBuilderState extends State<RoutineBuilder>
         height: 124,
         padding: const EdgeInsets.all(12),
         decoration: BoxDecoration(
-          borderRadius: BorderRadius.circular(16),
+          borderRadius: BorderRadius.zero,
           gradient: selected
               ? LinearGradient(
                   begin: Alignment.topLeft,
@@ -424,7 +424,6 @@ class RoutineBuilderState extends State<RoutineBuilder>
                 color: selected
                     ? colorWhite.withValues(alpha: 0.16)
                     : kindBackground(kind),
-                shape: BoxShape.circle,
               ),
               child: Icon(kindIcon(kind),
                   size: 17, color: selected ? colorWhite : tone),
@@ -470,7 +469,7 @@ class RoutineBuilderState extends State<RoutineBuilder>
         padding: const EdgeInsets.fromLTRB(14, 12, 14, 12),
         decoration: BoxDecoration(
           color: applied ? kindBackground(_routine.kind) : colorWhite,
-          borderRadius: BorderRadius.circular(14),
+          borderRadius: BorderRadius.zero,
           border: Border.all(
             color: applied
                 ? kindColor(_routine.kind).withValues(alpha: 0.4)
@@ -515,7 +514,6 @@ class RoutineBuilderState extends State<RoutineBuilder>
             alignment: Alignment.center,
             decoration: BoxDecoration(
               color: on ? tone : colorWhite,
-              shape: BoxShape.circle,
               border: Border.all(color: on ? tone : colorBorder),
             ),
             child: text(weekdayInitial(day), 13,
@@ -576,7 +574,7 @@ class RoutineBuilderState extends State<RoutineBuilder>
               alignment: Alignment.center,
               decoration: BoxDecoration(
                 color: kindBackground(_routine.kind),
-                borderRadius: BorderRadius.circular(9),
+                borderRadius: BorderRadius.zero,
               ),
               child: text("${index + 1}", 12, TextType.Bold, color: tone),
             ),