feat: implement full Bonsai design — bottom nav, green theme, redesigned screens

- Replace drawer + TopAppBar with bottom tab bar (Aujourd'hui / Prévu / Projets / Profil)
- Update theme to forest green (#2F7A4F) + warm cream (#F1ECE0) palette (light & dark)
- TodayScreen: header with date, hero progress ring showing done/total tasks
- ScheduledScreen: horizontal week strip with today highlighted
- ProjectScreen: full-width green banner with done/remaining/progress stats
- ProjectsListScreen: new screen with 2×2 quick tiles + project list with progress rings
- TaskRow: card-style with rounded border, circular checkbox
- Add getDoneTodayCount() to DAO/Repository/ViewModel for progress tracking
- Route.ProjectsList added; start destination changed to Today

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/build.gradle.kts

@@ -16,7 +16,7 @@ android {
         minSdk = 26
         targetSdk = 35
         versionCode = 1
-        versionName = "0.0.17"
+        versionName = "0.0.18"
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }