Version 1.7.0: Feather Icons via Qt-Ressourcensystem eingebunden

Alle QIcon.fromTheme()-Aufrufe durch eingebettete Feather Icons ersetzt,
die unter Windows zuverlässig funktionieren. Icons passen sich automatisch
der Palette-Farbe des aktiven Themes an (QSvgRenderer + currentColor).

- scripts/download_icons.py: lädt 20 Feather-SVGs von GitHub
- src/res/icons/: 20 SVG-Dateien (MIT-Lizenz, stroke=currentColor)
- src/res/resources.qrc + resources_rc.py: Qt-Ressourcensystem
- src/icons.py: icon()-Hilfsfunktion mit Palette-Farb-Injection
- MainWindow, AppSettings, XslDependencyDialog, tree_manager,
  XsltParamsEditDialog, ProjectXsltParamsDialog: Icons gesetzt
- Theme-Wechsel aktualisiert Icons und Tree-Items sofort
- THIRD_PARTY_LICENSES.txt: Feather Icons (MIT) eingetragen

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

scripts/download_icons.py

@@ -0,0 +1,76 @@
+"""
+Lädt Feather Icons (MIT-Lizenz) von GitHub herunter und speichert sie in src/res/icons/.
+Stroke-Farbe wird auf #444444 gesetzt für bessere Sichtbarkeit in hellen und dunklen Themes.
+
+Ausführung: uv run python scripts/download_icons.py
+"""
+
+import urllib.request
+from pathlib import Path
+
+ICONS = [
+    "folder-plus",
+    "log-out",
+    "settings",
+    "folder",
+    "refresh-cw",
+    "plus-circle",
+    "minus-circle",
+    "play-circle",
+    "file",
+    "check-circle",
+    "info",
+    "git-branch",
+    "file-text",
+    "code",
+    "chevron-down",
+    "chevron-up",
+    "trash-2",
+    "file-plus",
+    "columns",
+    "sliders",
+    "folder-open",
+]
+
+BASE_URL = "https://raw.githubusercontent.com/feathericons/feather/master/icons/{name}.svg"
+OUTPUT_DIR = Path(__file__).parent.parent / "src" / "res" / "icons"
+
+
+def download_icons():
+    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
+
+    success = 0
+    failed = []
+
+    for name in ICONS:
+        url = BASE_URL.format(name=name)
+        dest = OUTPUT_DIR / f"{name}.svg"
+
+        if dest.exists():
+            print(f"  [OK] {name}.svg (bereits vorhanden)")
+            success += 1
+            continue
+
+        try:
+            with urllib.request.urlopen(url, timeout=10) as response:
+                content = response.read().decode("utf-8")
+
+            content = content.replace('stroke="#000000"', 'stroke="#444444"')
+            content = content.replace("stroke='#000000'", "stroke='#444444'")
+
+            dest.write_text(content, encoding="utf-8")
+            print(f"  [OK] {name}.svg")
+            success += 1
+
+        except Exception as e:
+            print(f"  [FEHLER] {name}.svg: {e}")
+            failed.append(name)
+
+    print(f"\n{success}/{len(ICONS)} Icons heruntergeladen nach {OUTPUT_DIR}")
+    if failed:
+        print(f"Fehlgeschlagen: {', '.join(failed)}")
+
+
+if __name__ == "__main__":
+    print(f"Lade {len(ICONS)} Feather Icons herunter ...")
+    download_icons()