server: install volkswagencarnet from GitHub + apply auth patch

requirements.txt now references the upstream GitHub repo pinned to
commit c30dc37 (the last upstream commit before our fix), so the source
is portable and not machine-specific.

install.sh applies cariad-hybrid-auth-fix.patch to the installed
site-packages after pip runs, using `patch -N` so it is idempotent on
repeat installs.  The patch file is checked in to the repo so install.sh
can always find it.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/install.sh

@@ -56,6 +56,17 @@ fi
 echo "==> Installing / updating dependencies"
 "$VENV/bin/pip" install --quiet --upgrade pip
 "$VENV/bin/pip" install --quiet --upgrade -r "$SCRIPT_DIR/requirements.txt"
+
+echo "==> Applying cariad-hybrid-auth-fix.patch to volkswagencarnet"
+SITE_PKG="$("$PYTHON" -c 'import sysconfig; print(sysconfig.get_path("purelib"))')"
+PATCH_FILE="$REPO_DIR/cariad-hybrid-auth-fix.patch"
+if patch -d "$SITE_PKG" -p1 -N --dry-run --silent < "$PATCH_FILE" 2>/dev/null; then
+    patch -d "$SITE_PKG" -p1 -N --silent < "$PATCH_FILE"
+    echo "    Patch applied"
+else
+    echo "    Patch already applied (skipping)"
+fi
+
 echo "    Python  : $PYTHON"
 echo ""