Redesign the UI after the fitness reference and replace the logo

Light sage-to-cream ambient backdrop, frosted glass controls and painted
SceneArt landscapes in place of photography. Home becomes a dashboard with a
two-tone greeting, a frosted summary ring, category portraits, an up-next rail
of image-led cards and a floating glass tab bar. The routine library gets an
image header and painted cards; the player gets a scene stage, steps on an
arc, a dotted clock and a night pill with a lime spark. Goals become painted
cards in their own colour.

New logo: a lime sun resting on a ground line under two arcs. The splash
raises the sun and lights the arcs; launcher icons and native splash are
regenerated to match.

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

frontend/web/manifest.json

@@ -3,8 +3,8 @@
     "short_name": "grounded",
     "start_url": ".",
     "display": "standalone",
-    "background_color": "#141414",
-    "theme_color": "#141414",
+    "background_color": "#EAEFE6",
+    "theme_color": "#18211C",
     "description": "A new Flutter project.",
     "orientation": "portrait-primary",
     "prefer_related_applications": false,