Improve the installer, fix context menu on Windows, add CI workflows

scripts/ci-set-version.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+VERSION="${1:?usage: ci-set-version.sh <version>}"
+VERSION_CODE="$(printf '%s' "$VERSION" | sed 's/[^0-9]//g')"
+if [[ -z "$VERSION_CODE" ]]; then
+  VERSION_CODE=1
+fi
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+GRADLE_FILE="$ROOT/build.gradle.kts"
+
+sed -i.bak "s/extra\\[\"versionName\"\\] = \"[^\"]*\"/extra[\"versionName\"] = \"$VERSION\"/" "$GRADLE_FILE"
+sed -i.bak "s/extra\\[\"versionCode\"\\] = [0-9]*/extra[\"versionCode\"] = $VERSION_CODE/" "$GRADLE_FILE"
+rm -f "$GRADLE_FILE.bak"
+
+echo "versionName=$VERSION versionCode=$VERSION_CODE"