Draw the whole interface in Compose

Etappen 3 to 6a of the migration (129 commits). Every window the operator sees
is Compose; the JavaFX ones still exist beside them so the two could be
compared against a live session, which is the only way the differences came to
light.

The toolchain first, then the settings window with its eleven tabs and 72 real
preferences; then the multi-column table as a component, and with it the rules
it needs -- stable row identity, a selection that survives a refresh, column
order the operator can drag, and a repaint when the rows change rather than
when the list instance does. Then the update and monitor windows, and the main
window: 22 station columns, the filter bar, the selected-station panel, the
message tabs, the priority bar, the sked controls, the status indicators and
the timeline, assembled behind a splitter because Compose has none.

The map stops being a WebView. A Compose canvas projects WebMercator tiles
itself, with the clustering in core and an asynchronous fetcher in place of the
local tile proxy; derive() becomes a pure Kotlin reimplementation instead of a
reflection call into com.sun.javafx.

Most of the volume here is parity the operator would notice rather than new
behaviour: desktop density instead of Material's phone minimums, colours taken
from the JavaFX stylesheets instead of Material's palette, row dividers, band
columns, grid-square labels and their colours, the home marker and antenna
beam, pinch-to-zoom under Wayland, and layouts that survive a window narrower
than the chart they stack.

Two lessons are worth more than the diff. A control bound to a value Compose
cannot observe writes through and never redraws -- that one shipped repeatedly
with a green build, because no test drew anything. And a layout that clips
instead of wrapping is worse than one that is merely too narrow: half a word
is the worst available outcome.

packaging/aur/kst4contest-git/PKGBUILD

@@ -26,19 +26,13 @@ build() {
     export JAVA_HOME=$(find /usr/lib/jvm -maxdepth 1 -name 'java-21-*' -type d | head -n 1)
     export PATH="${JAVA_HOME}/bin:${PATH}"
 
-    ./gradlew --offline -S :app-desktop:collectRuntime
+    ./gradlew --offline -S :app-desktop:createDistributable
 
+    # package() reads dist/KST4Contest. Application name, icon and the JDK
+    # module list come from app-desktop/build.gradle.kts.
+    rm -rf dist
     mkdir -p dist
-    ADD_MODULES="$(grep -m1 '^jpackageAddModules=' gradle.properties | cut -d= -f2)"
-    jpackage \
-        --type app-image \
-        --name KST4Contest \
-        --icon packaging/icons/kst4contest.png \
-        --input app-desktop/build/dist-libs \
-        --main-jar app.jar \
-        --main-class kst4contest.view.Main \
-        --add-modules "$ADD_MODULES" \
-        --dest dist
+    cp -a app-desktop/build/compose/binaries/main/app/KST4Contest dist/
 }
 
 package() {

packaging/aur/kst4contest/PKGBUILD

@@ -19,34 +19,14 @@ build() {
     export JAVA_HOME=$(find /usr/lib/jvm -maxdepth 1 -name 'java-21-*' -type d | head -n 1)
     export PATH="${JAVA_HOME}/bin:${PATH}"
 
-    ./gradlew --offline -S :app-desktop:collectRuntime
+    ./gradlew --offline -S :app-desktop:createDistributable
 
+    # package() reads dist/KST4Contest. Application name, icon and the JDK
+    # module list come from app-desktop/build.gradle.kts, so this PKGBUILD no
+    # longer has to keep its own copy of them.
+    rm -rf dist
     mkdir -p dist
-    # From the Gradle build onwards the list lives in gradle.properties. Older
-    # tarballs still carry it in pom.xml or derive it via packaging/AddModules.java.
-    if [ -f gradle.properties ]; then
-        ADD_MODULES="$(grep -m1 '^jpackageAddModules=' gradle.properties | cut -d= -f2)"
-    elif [ -f packaging/AddModules.java ]; then
-        ADD_MODULES="$(java packaging/AddModules.java)"
-    else
-        ADD_MODULES="$(sed -n 's:.*<addmodule>\(.*\)</addmodule>.*:\1:p' pom.xml | paste -sd,)"
-    fi
-    # Same story for the packaging icon: without --icon jpackage silently ships
-    # its own Duke placeholder, but tarballs older than v1.42.0 have no icon to
-    # point at, so only pass the flag when the file is actually there.
-    ICON_ARGS=()
-    if [ -f packaging/icons/kst4contest.png ]; then
-        ICON_ARGS=(--icon packaging/icons/kst4contest.png)
-    fi
-    jpackage \
-        --type app-image \
-        --name KST4Contest \
-        "${ICON_ARGS[@]}" \
-        --input app-desktop/build/dist-libs \
-        --main-jar app.jar \
-        --main-class kst4contest.view.Main \
-        --add-modules "$ADD_MODULES" \
-        --dest dist
+    cp -a app-desktop/build/compose/binaries/main/app/KST4Contest dist/
 }
 
 package() {

packaging/macos/build-signed-dmg.sh

@@ -4,8 +4,9 @@
 #
 # jpackage cannot sign the app itself: it ad-hoc signs the embedded runtime and
 # then re-runs codesign on the same files without --force, which codesign
-# rejects with "is already signed". So this builds an unsigned app-image, signs
-# it from the inside out ourselves, and only then wraps it into a DMG.
+# rejects with "is already signed". So this takes the unsigned bundle from
+# :app-desktop:createDistributable, signs it from the inside out ourselves, and
+# only then wraps it into a DMG.
 #
 # Required:
 #   SIGNING_IDENTITY   The name part of the Developer ID Application certificate,
@@ -49,38 +50,29 @@ elif [ -n "${NOTARY_PROFILE:-}" ]; then
     NOTARY_ARGS=(--keychain-profile "$NOTARY_PROFILE")
 fi
 
-echo "==> Building JAR and collecting runtime dependencies"
+# The DMG carries the same version the Compose packaging stamps into the
+# bundle. gradle.properties keeps that value free of a qualifier, because the
+# DMG and MSI formats reject one.
+APP_VERSION="$(grep -m1 '^composePackageVersion=' gradle.properties | cut -d= -f2)"
+[ -n "$APP_VERSION" ] || { echo "composePackageVersion missing from gradle.properties" >&2; exit 1; }
+echo "==> Bundle version: $APP_VERSION"
+
+echo "==> Step 1/4: building the unsigned app bundle"
 chmod +x gradlew
-./gradlew -S :app-desktop:collectRuntime
+# createDistributable builds the bundle including its jlinked runtime. Name,
+# icon, bundle identifier and the JDK module list all come from
+# app-desktop/build.gradle.kts, so this script cannot drift from the CI build.
+MACOSX_DEPLOYMENT_TARGET="13.0" ./gradlew -S :app-desktop:createDistributable
 
-# jpackage only accepts a numeric major[.minor[.patch]] as the macOS bundle
-# version, so a Maven qualifier like "-nightly" has to be trimmed off.
-POM_VERSION="${JAR##*/praktiKST-}"
-POM_VERSION="${POM_VERSION%.jar}"
-APP_VERSION="$(printf '%s' "$POM_VERSION" | sed -e 's/[^0-9.].*$//' -e 's/\.*$//')"
-[ -n "$APP_VERSION" ] || { echo "Could not derive app version from $JAR" >&2; exit 1; }
-echo "==> Version: $POM_VERSION -> bundle version $APP_VERSION"
-
-echo "==> Step 1/4: jpackage app-image (unsigned)"
 rm -rf dist
-mkdir -p dist
-ADD_MODULES="$(grep -m1 '^jpackageAddModules=' gradle.properties | cut -d= -f2)"
-
-MACOSX_DEPLOYMENT_TARGET="13.0" jpackage \
-    --type app-image \
-    --name KST4Contest \
-    --app-version "$APP_VERSION" \
-    --icon packaging/icons/kst4contest.icns \
-    --input app-desktop/build/dist-libs \
-    --main-jar app.jar \
-    --main-class kst4contest.view.Main \
-    --add-modules "$ADD_MODULES" \
-    --mac-package-identifier "$BUNDLE_ID" \
-    --mac-package-name KST4Contest \
-    --dest dist/appimage
+mkdir -p dist/appimage
+# ditto and not cp -R: the signing steps below depend on extended attributes,
+# and only ditto preserves them.
+ditto app-desktop/build/compose/binaries/main/app/KST4Contest.app \
+    dist/appimage/KST4Contest.app
 
 APP="dist/appimage/KST4Contest.app"
-[ -d "$APP" ] || { echo "jpackage produced no app image" >&2; exit 1; }
+[ -d "$APP" ] || { echo "createDistributable produced no app bundle" >&2; exit 1; }
 
 echo "==> Step 2/4: signing bundle contents (this takes a few minutes)"