home: Today progress ring + live Upcoming preview

Rework the overview's 2x2 smart grid into a daily-momentum layout:

- Promote Today into a full-width hero with an M3 Expressive
  CircularWavyProgressIndicator over "x of y done" for tasks due today.
  Empty/all-done states read as a calm finished state, not a bare 0.
- Drop the white "Upcoming 0" tile (it shouted loudest while carrying the
  least) in favour of a live preview of the next few upcoming tasks, each a
  slim row with the quiet meta line and a tap-through to the task.
- Overdue + All fall back to a 2-up of the existing tonal tiles.

ListsViewModel now combines a Smart(COMPLETED) flow so the ring can count
the tasks already ticked off today (the open smart lists drop them).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/res/values/strings.xml

@@ -129,6 +129,17 @@
     <string name="smart_all">All</string>
     <string name="open_count">%1$d open</string>
 
+    <!-- Home: Today progress hero -->
+    <string name="home_today_progress">%1$d of %2$d done</string>
+    <string name="home_today_remaining">%1$d left</string>
+    <string name="home_today_all_done">All done 🎉</string>
+    <string name="home_today_empty">Nothing due today 🎉</string>
+
+    <!-- Home: Upcoming preview -->
+    <string name="home_upcoming_view_all">View all</string>
+    <string name="home_due_today">Today</string>
+    <string name="home_due_tomorrow">Tomorrow</string>
+
     <!-- Reminders -->
     <string name="reminder_due_at">Due %1$s</string>
     <string name="reminder_channel_name">Task reminders</string>