release: cut v2.0.0 — write support complete

Version bumped to 2.0.0 / 13. No code changes beyond the version — 2.0.0
closes out Milestone 2 (write support, v1.1 through v2.0): the final slice
is the save-conflict dialog (external change → overwrite/discard, external
delete → informational close), plus the store refresh: descriptions and
README describe write support and reminders, and fastlane screenshots
(DE+EN, six each) ship for F-Droid. CHANGELOG [2.0.0] carries the details.

Quick-add was cut from scope (the prefilled form covers it); calendar
switching while editing moved to the v3 backlog. Both documented in the
roadmap.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.0.0] — 2026-06-11
+
 ### Added
 - Conflict handling when saving an edit: if the event changed elsewhere
   (sync, another device) while the form was open, saving now asks whether
@@ -20,6 +22,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - F-Droid description and README no longer claim the app is read-only —
   they now describe write support and reminder delivery
 
+### Fixed
+- `versionName`/`versionCode` bumped to 2.0.0 / 13 — closing out the
+  write-support milestone (v1.1 through v2.0)
+
 ## [1.4.0] — 2026-06-11
 
 ### Added