chore(v1.8.0): IMPL_05 Version Bump - v1.7.2 → v1.8.0

- Update versionCode from 19 to 20
- Update versionName from "1.7.2" to "1.8.0"
- Create F-Droid changelog for versionCode 20 (EN + DE)
- Update CHANGELOG.md with comprehensive v1.8.0 entry (all 16 features)
- Update CHANGELOG.de.md with German v1.8.0 entry
- Add commit hashes to all changelog entries for traceability

Major feature release: Widgets with interactive checklists, note/checklist
sorting, server deletion detection, sync status legend, live sync progress,
parallel downloads, checklist UX improvements, and widget text display fix.
Complete changelog lists all features with commit references.

fastlane/metadata/android/en-US/changelogs/20.txt

@@ -0,0 +1,12 @@
+🎉 v1.8.0 — WIDGETS, SORTING & SYNC IMPROVEMENTS
+
+• New: Home screen widgets with interactive checkboxes
+• New: Note sorting (date, title, type)
+• New: Checklist auto-sort (unchecked first/checked last)
+• New: Server deletion detection for multi-device sync
+• New: Sync status legend (help button explains all icons)
+• Improved: Live sync progress with phase indicators
+• Improved: Parallel downloads for faster sync
+• Improved: Checklist overflow gradient for long text
+• Fixed: Drag & drop flicker in checklists
+• Fixed: Widget text notes scrolling