chore: initialize project structure for Sprint 0

.gitignore

@@ -0,0 +1,51 @@
+# Godot 4 project files to ignore
+
+# Godot generated files
+.godot/
+.import/
+
+# Godot-specific ignores
+export.cfg
+export_presets.cfg
+
+# Imported translations (automatically generated from CSV files)
+*.translation
+
+# Mono-specific ignores (falls C# verwendet wird)
+.mono/
+data_*/
+mono_crash.*.json
+
+# System/IDE files
+.DS_Store
+Thumbs.db
+*.swp
+*.swo
+*~
+.idea/
+.vscode/
+*.tmp
+
+# Build outputs
+builds/
+export/
+*.apk
+*.aab
+*.ipa
+
+# Android keystore (NIEMALS ins Repo!)
+*.keystore
+*.jks
+android/release.keystore
+
+# Secrets
+secrets.cfg
+.env
+.env.local
+
+# Logs
+*.log
+logs/
+
+# OS-spezifisch
+desktop.ini