fix: iOS 26 Liquid Glass 탭바 투명 배경 적용

- UITabBarAppearance configureWithDefaultBackground 설정
- 코스 발견/보관함 콘텐츠 bottom을 superview로 확장 (iOS 26)
- Liquid Glass가 뒤 콘텐츠를 비추도록 레이아웃 수정

Author: thingineeer

Runnect-iOS/Runnect-iOS/Presentation/CourseDiscovery/Views/VC/CourseDiscoveryVC.swift

@@ -301,7 +301,12 @@ extension CourseDiscoveryVC {
 
         mapCollectionView.snp.makeConstraints {
             $0.top.equalTo(self.naviBar.snp.bottom)
-            $0.leading.bottom.trailing.equalTo(view.safeAreaLayoutGuide)
+            $0.leading.trailing.equalTo(view.safeAreaLayoutGuide)
+            if #available(iOS 26, *) {
+                $0.bottom.equalToSuperview()
+            } else {
+                $0.bottom.equalTo(view.safeAreaLayoutGuide)
+            }
         }
 
         uploadButton.snp.makeConstraints {

Runnect-iOS/Runnect-iOS/Presentation/CourseStorage/VC/CourseStorageVC.swift

@@ -225,7 +225,12 @@ extension CourseStorageVC {
 
         viewPager.snp.makeConstraints {
             $0.top.equalTo(naviBar.snp.bottom)
-            $0.leading.bottom.trailing.equalTo(view.safeAreaLayoutGuide)
+            $0.leading.trailing.equalTo(view.safeAreaLayoutGuide)
+            if #available(iOS 26, *) {
+                $0.bottom.equalToSuperview()
+            } else {
+                $0.bottom.equalTo(view.safeAreaLayoutGuide)
+            }
         }
 
         deleteCourseButton.snp.makeConstraints {

Runnect-iOS/Runnect-iOS/Presentation/TabBar/TabBarController.swift

@@ -31,7 +31,11 @@ extension TabBarController {
             // iOS 26+: Liquid Glass 활용
             tabBar.tintColor = .m1
             tabBar.unselectedItemTintColor = .g3
-            // 시스템 Liquid Glass 스타일 사용 — 커스텀 배경/코너 제거
+            // Liquid Glass 활성화: 시스템 기본 반투명 외관 설정
+            let appearance = UITabBarAppearance()
+            appearance.configureWithDefaultBackground()
+            tabBar.standardAppearance = appearance
+            tabBar.scrollEdgeAppearance = appearance
         } else {
             // iOS 25 이하: 기존 커스텀 스타일 유지
             tabBar.backgroundColor = .white