chore: migrate groupId from se.lfv.reqstool to io.github.reqstool

- Update pom.xml groupId to io.github.reqstool
- Rename package structure from se.lfv.reqstool to io.github.reqstool
- Update all imports and package declarations
- Update annotation processor @SupportedAnnotationTypes references
- Update test resource files with new package names
- All tests passing

Author: jimisola

.claude/settings.local.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(mvn clean:*)"
+    ]
+  }
+}