release: cut v1.3.0 — event edit

Version bumped to 1.3.0 / 11. No code changes beyond the version — 1.3.0 is
the reviewed-and-approved edit slice: shared form for editing, scope-at-save
for recurring events (this / this and following / all, exception rows and
series splits), three-way recurring delete, simple recurrence picker with
weekly weekday toggles, and the stale-instances split fix. CHANGELOG [1.3.0]
carries the details.

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

app/build.gradle.kts

@@ -23,8 +23,8 @@ android {
         applicationId = "de.jeanlucmakiola.calendula"
         minSdk = 29
         targetSdk = 36
-        versionCode = 10
-        versionName = "1.2.1"
+        versionCode = 11
+        versionName = "1.3.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }