semesterprojekt: implement full text adventure (phases 1-7)

Walking skeleton through Swing GUI: YAML-driven world (4 rooms,
4 items, 1 NPC), HashMap command dispatch with parser, three-tier
item hierarchy (readable / switchable / plain), and end-to-end
NPC give/receive flow. 67 tests green.

Semesterprojekt/.gitignore

@@ -0,0 +1,39 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+.kotlin
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store