Document the desktop's actual build setup and the release procedure

The desktop (jonas@192.168.1.86) has no ~/jdk21 and no ~/android-sdk; its
checkout is ~/sources/Kvaesitso, the SDK is ~/Android/Sdk and it builds with
Arch's java-21-openjdk. Also record how the APK gets published, since that
was only in the release checklist of these notes.

CLAUDE.md

@@ -87,7 +87,7 @@ state in `ui/settings/clockwidget/ClockWidgetSettingsScreenVM.kt`. New strings a
 
 On the desktop:
 
-    JAVA_HOME=~/jdk21 ANDROID_HOME=~/android-sdk \
+    JAVA_HOME=/usr/lib/jvm/java-21-openjdk ANDROID_HOME=~/Android/Sdk \
       ./gradlew :app:app:assembleDefaultRelease
 
 Result: `app/app/build/outputs/apk/default/release/app-default-release.apk`, applicationId
@@ -99,6 +99,21 @@ in the repository root (git-ignored) or the `KEYSTORE_FILE`, `KEYSTORE_PASSWORD`
 `~/android-keystores/kvaesitso-release.jks`; the phone has its own copy under
 `~/android-keystores/` in the Termux home.
 
+The desktop's checkout (jonas@192.168.1.86) is `~/sources/Kvaesitso`. Its SDK is `~/Android/Sdk`
+(platforms android-35/37.0, build-tools 34/36/37), so `local.properties` there has
+`sdk.dir=/home/jonas/Android/Sdk`, and `keystore.properties` points at the copy of the release key
+in `~/android-keystores/`. It has no `~/jdk21`; it uses Arch's `java-21-openjdk`.
+
+After the APK is built (on either machine), the release is tagged and published from the phone:
+
+    git tag -a v1.40.2-typing.N -m "Kvaesitso 1.40.2 type-to-search and agenda, Nth build"
+    git push origin main v1.40.2-typing.N
+
+and a Gitea release for that tag is created with the APK attached as
+`Kvaesitso-v<versionName>-Signed.apk` (the token is in `~/.config/gitea/token`; the API is
+`POST /api/v1/repos/jonas/Kvaesitso/releases` and then `.../releases/<id>/assets?name=<asset>` with
+`-F attachment=@<apk>`).
+
 ### Building on the phone itself (Termux)
 
 The phone builds this project without a desktop. `scripts/ondevice.sh` wraps the loop: