fix: 애니메이션 개선 및 APK 업데이트

- ViewPropertyAnimator 사용으로 더 부드러운 전환
- alpha 애니메이션 추가로 시각적 효과 개선
- APK URL 업데이트

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

app/src/main/java/com/example/shiftalarm/MainActivity.kt

@@ -706,37 +706,39 @@ class MainActivity : AppCompatActivity() {
         }
     }
     private fun animateMonthTransition(direction: Int) {
-        val slideOut = if (direction > 0) {
-            android.view.animation.TranslateAnimation(0f, -binding.calendarCard.width.toFloat(), 0f, 0f)
-        } else {
-            android.view.animation.TranslateAnimation(0f, binding.calendarCard.width.toFloat(), 0f, 0f)
-        }
-        slideOut.duration = 150
-        slideOut.fillAfter = false
-
-        val slideIn = if (direction > 0) {
-            android.view.animation.TranslateAnimation(binding.calendarCard.width.toFloat(), 0f, 0f, 0f)
-        } else {
-            android.view.animation.TranslateAnimation(-binding.calendarCard.width.toFloat(), 0f, 0f, 0f)
-        }
-        slideIn.duration = 150
-        slideIn.fillAfter = true
-
-        binding.calendarCard.startAnimation(slideOut)
+        val card = binding.calendarCard
+        val width = card.width.toFloat()
         
-        slideOut.setAnimationListener(object : android.view.animation.Animation.AnimationListener {
-            override fun onAnimationStart(animation: android.view.animation.Animation?) {}
-            override fun onAnimationRepeat(animation: android.view.animation.Animation?) {}
-            override fun onAnimationEnd(animation: android.view.animation.Animation?) {
+        if (width == 0f) {
+            currentViewMonth = if (direction > 0) {
+                currentViewMonth.plusMonths(1)
+            } else {
+                currentViewMonth.minusMonths(1)
+            }
+            updateCalendar()
+            return
+        }
+        
+        card.animate()
+            .translationX(if (direction > 0) -width else width)
+            .alpha(0.5f)
+            .setDuration(200)
+            .withEndAction {
                 currentViewMonth = if (direction > 0) {
                     currentViewMonth.plusMonths(1)
                 } else {
                     currentViewMonth.minusMonths(1)
                 }
                 updateCalendar()
-                binding.calendarCard.startAnimation(slideIn)
+                
+                card.translationX = if (direction > 0) width else -width
+                card.animate()
+                    .translationX(0f)
+                    .alpha(1f)
+                    .setDuration(200)
+                    .start()
             }
-        })
+            .start()
     }
 
     private fun formatRemainingDays(days: Float): String {