Restyle to match getartcraft.com, add an installer wizard, blue app icon (#23)

The launcher now looks like the apps page on getartcraft.com: the site's
colour tokens, square corners, 1 px hairlines instead of shadows, app cards
in a shared-hairline grid with numbered tabs and "Photo*Craft*" wordmarks,
mono upper-case labels and buttons, and square badges for status.

Fonts are the site's own, embedded in the binary: Archivo (620, 118 % width)
for headings and app names, Inter for body text and Geist Mono for labels,
all variable fonts from google/fonts (OFL-1.1) set to the site's weights.

The window has a custom title bar on Windows and Linux (drag to move,
double-click to maximize, minimize/maximize/close, resize from the edges)
and a transparent one on macOS with the traffic lights in the header.

The MSI used to flash a progress bar and close. Double-clicked, it now opens
a WixUI wizard (Welcome, Ready, progress, Finish with "Launch ArtCraft
Launcher"), with art drawn by package.ps1 from the ArtCraft mark and the
Craft apps' icons. Self-update still runs it with /passive. CI installs the
WiX UI and Util extensions.

The app icon is now the blue "A" mark, getartcraft.com's favicon.
packaging/icons.sh runs on any OS: `cargo xtask icns` packs the .icns.

Also: two clippy fixes in crates/native that newer clippy rejects, and
refreshed README screenshots.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/packaging-lint.yml

@@ -51,7 +51,7 @@ jobs:
           ./packaging/windows/check-icons.ps1
       - name: XML, desktop entry, AppStream, Flatpak manifest
         run: |
-          xmllint --noout packaging/windows/artcraft-launcher.wxs packaging/macos/*.plist* packaging/linux/*.xml*
+          xmllint --noout packaging/windows/artcraft-launcher.wxs packaging/windows/artcraft-launcher.en-us.wxl packaging/macos/*.plist* packaging/linux/*.xml*
           if grep -q "<key>LSUIElement</key>" packaging/macos/Info.plist.in; then echo "::error::Info.plist.in must not set LSUIElement"; exit 1; fi
           desktop-file-validate packaging/linux/ai.storyteller.artcraft-launcher.desktop
           sed -e 's/@VERSION@/0.0.0/' -e 's/@DATE@/2026-01-01/' packaging/linux/ai.storyteller.artcraft-launcher.metainfo.xml.in >"$RUNNER_TEMP/ai.storyteller.artcraft-launcher.metainfo.xml"

.github/workflows/release.yml

@@ -143,7 +143,9 @@ jobs:
         run: cargo xtask version set "$ARTCRAFT_LAUNCHER_VERSION"
       - name: Install WiX
         shell: pwsh
-        run: dotnet tool install --global wix --version 5.0.2
+        run: |
+          dotnet tool install --global wix --version 5.0.2
+          wix extension add -g WixToolset.UI.wixext/5.0.2 WixToolset.Util.wixext/5.0.2
       - name: Build, sign, package
         shell: pwsh
         env:

.github/workflows/windows-arm64.yml

@@ -41,7 +41,9 @@ jobs:
           key: windows-arm64-package
       - name: Install WiX
         shell: pwsh
-        run: dotnet tool install --global wix --version 5.0.2
+        run: |
+          dotnet tool install --global wix --version 5.0.2
+          wix extension add -g WixToolset.UI.wixext/5.0.2 WixToolset.Util.wixext/5.0.2
       - name: Build and package (unsigned)
         shell: pwsh
         env: