feat: add custom house launcher icon, themed splash screen, and F-Droid metadata

Replace default Flutter icon with white house on sage green (#7A9A6D) background.
Add native splash screen with themed colors (#F5F0E8 light, #2A2520 dark).
Include F-Droid metadata with screenshots for de-DE and en-US locales.
Add CHANGELOG.md tracking all releases from v1.0.0 to v1.1.3.

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

CHANGELOG.md

@@ -0,0 +1,47 @@
+# Changelog
+
+All notable changes to HouseHoldKeeper are documented in this file.
+
+## [1.1.3] - 2026-03-17
+
+### Added
+- Custom app launcher icon — white house on sage green background
+- Adaptive icon support for Android 8+ (API 26)
+- Native splash screen with themed colors (beige light / brown dark)
+- Android 12+ splash screen with icon background
+- F-Droid metadata (de-DE, en-US) with screenshots and descriptions
+- F-Droid metadata copy step in release workflow
+
+## [1.1.2] - 2026-03-17
+
+### Changed
+- Release workflow now sets Flutter app version from Git tag automatically
+
+## [1.1.1] - 2026-03-17
+
+### Added
+- Integration tests for filtered and overdue task states in TaskListScreen
+
+## [1.1.0] - 2026-03-17
+
+### Added
+- Calendar strip on home screen with day-by-day task overview
+- Floating "Today" button for quick navigation
+- Task history sheet showing past completions per task
+- Task sorting by name, due date, or room with persistent preference
+- Sort dropdown in HomeScreen and TaskListScreen
+
+### Changed
+- HomeScreen replaced with calendar-based composition
+
+## [1.0.0] - 2026-03-16
+
+### Added
+- Initial MVP release
+- Room management with drag-and-drop reordering
+- Task creation with templates and custom tasks
+- Recurring task scheduling (daily, weekly, monthly, yearly)
+- Local notifications for due tasks
+- German and English localization
+- Light and dark theme support
+- Local-only SQLite database (drift)