Rebuild Home around a forest header with streak, score and water

Home now opens on a deep green header: greeting, a Today / Weekly toggle,
a seven-day streak with a leaf on every kept day, minutes held with a +
ring, plan thumbnails, the report-card letter as the score, and one bar per
commitment class (weekly view swaps in per-day bars and class rates). The
+ opens an "Add to today" sheet over the blurred day. A water tracker sits
below the header, kept on the device. The nav marks the selected tab as a
filled block and drops the side action button.

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

frontend/lib/Grounded/memory/InternalMemory.dart

@@ -41,6 +41,8 @@ class InternalMemory implements ConnectInternalMemory {
 
   static const String AMNESTY_SPENT = "AMNESTY_SPENT_Jr4xVh9KmT3gLc6B";
 
+  static const String WATER = "WATER_Qe7tNd4ZsM2kBv9C";
+
   static const String TODOS = "TODOS_Wm3kRb8TqZ5nHc2F";
 
   static const String SHOW_ONBOARDING = "SHOW_ONBOARDING_Nz6qGf2SdX7wPb4M";
@@ -255,6 +257,31 @@ class InternalMemory implements ConnectInternalMemory {
     await groundedStorage.write(key: AMNESTY_SPENT, value: spent.toString());
   }
 
+  String _today() {
+    final DateTime now = DateTime.now();
+    return "${now.year}-${now.month}-${now.day}";
+  }
+
+  @override
+  Future<int> getWaterToday() async {
+    String? value = await groundedStorage.read(key: WATER);
+
+    if (value != null) {
+      final Map<String, dynamic> entry = jsonDecode(value);
+      if (entry['day'] == _today()) {
+        return entry['ml'] ?? 0;
+      }
+    }
+
+    return 0;
+  }
+
+  @override
+  Future setWaterToday(int ml) async {
+    await groundedStorage.write(
+        key: WATER, value: jsonEncode({'day': _today(), 'ml': ml}));
+  }
+
   @override
   Future<List<TodoItem>> getTodos() async {
     String? value = await groundedStorage.read(key: TODOS);