Add standalone build and packaging workflow docs/scripts

build/build_linux.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT_DIR"
+
+PYTHON_BIN="${PYTHON_BIN:-.venv/bin/python}"
+
+if [ ! -x "$PYTHON_BIN" ]; then
+    echo "❌ Python nicht gefunden: $PYTHON_BIN"
+    echo "💡 Erwartet wird eine Virtual Environment unter .venv"
+    exit 1
+fi
+
+echo "🐧 Erstelle Linux-Standalone mit PyInstaller..."
+"$PYTHON_BIN" -m pip install --upgrade pip pyinstaller
+
+"$PYTHON_BIN" -m PyInstaller \
+    --noconfirm \
+    --clean \
+    --name "PDFtoICS" \
+    --windowed \
+    --add-data "version.txt:." \
+    gui_wxpython.py
+
+echo "✅ Fertig: dist/PDFtoICS"