refactor: change Boolean parameters to primitive boolean for advanced search in CourseController

Author: GravityDarkLab

server/skillforge-course/src/main/java/com/gitittogether/skillForge/server/course/controller/courses/CourseController.java

@@ -131,8 +131,8 @@ public ResponseEntity<List<CourseResponse>> searchCourses(
             @RequestParam(required = false) String skill,
             @RequestParam(required = false) String category,
             @RequestParam(required = false) String title,
-            @RequestParam(required = false) Boolean isPublished,
-            @RequestParam(required = false) Boolean isPublic
+            @RequestParam(required = false) boolean isPublished,
+            @RequestParam(required = false) boolean isPublic
     ) {
         log.info("Advanced search: instructor={}, level={}, language={}, skill={}, category={}, title={}, isPublished={}, isPublic={}",
                 instructor, level, language, skill, category, title, isPublished, isPublic);