release: cut 1.0.0 — Agendula keeps your tasks itself

versionName 1.0.0, versionCode 10000. Merging this to main triggers
.gitea/workflows/release.yaml, which builds it, publishes to the F-Droid repo,
and mints the v1.0.0 tag — and this is the release where `prerelease` flips to
false on its own, since the pipeline derives it from MAJOR.

CHANGELOG's 1.0.0 section covers the own store, list management, recurrence,
iCalendar export, the storage picker and the copy path, then the fixes to the
external-provider mode that 0.4.0 and earlier used for everything — the
reverting due times, the all-day drift, the silent save failure on tasks with a
duration, recurrence detection on tasks.org, the inert reminder field, and the
provider-failure recovery.

Nothing about the dropped authority or the custom permissions: they never
reached a release, so there is nothing for a user to have lost.

`changelogs/10000.txt` is `scripts/sync_changelog_to_fastlane.sh` output, for
the official F-Droid listing, at 471 of the 500 characters F-Droid will show —
the section is written to that budget rather than trimmed to fit it, since the
same text is the Gitea release notes. The detail behind each line is in the
commit messages, CHANGELOG's older entries stay as they were.

Still open before this merges, per docs/RELEASING.md step 4 and ROADMAP:
`./gradlew :app:connectedDebugAndroidTest` against the tip, and
`scripts/verify-release.sh` on a real device.

app/build.gradle.kts

@@ -27,10 +27,11 @@ android {
         // a bumped versionName into main triggers .gitea/workflows/release.yaml,
         // which builds this version and then creates the matching vX.Y.Z tag +
         // release itself (versionCode is pinned to MAJOR*10000 + MINOR*100 +
-        // PATCH from versionName, e.g. 0.2.0 -> 200). The Gitea release is marked
-        // as a pre-release while MAJOR is 0. See docs/RELEASING.md.
-        versionCode = 400
-        versionName = "0.4.0"
+        // PATCH from versionName, e.g. 1.0.0 -> 10000). Releases were flagged as
+        // pre-releases while MAJOR was 0; 1.0.0 is the first stable one, and the
+        // pipeline graduates it on its own. See docs/RELEASING.md.
+        versionCode = 10000
+        versionName = "1.0.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }