feat: v1.3.0 - versionCode 기반 업데이트 체크

- 버전 1.2.5 → 1.3.0 (versionCode 1130)
- AppUpdateManager: versionCode로 업데이트 비교
- versionName 비교 로직 제거
- 더 정확한 업데이트 감지

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/AppUpdateManager.kt

@@ -39,14 +39,21 @@ object AppUpdateManager {
                     reader.close()
 
                     val json = JSONObject(result)
+                    val serverVersionCode = json.getInt("versionCode")
                     val serverVersionName = json.getString("versionName")
                     val apkUrl = json.getString("apkUrl")
                     val changelog = json.optString("changelog", "버그 수정 및 성능 향상")
 
                     val pInfo = ctx.packageManager.getPackageInfo(ctx.packageName, 0)
+                    val currentVersionCode = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                        pInfo.longVersionCode.toInt()
+                    } else {
+                        @Suppress("DEPRECATION")
+                        pInfo.versionCode
+                    }
                     val currentVersionName = pInfo.versionName ?: "0.0.0"
 
-                    if (isNewerVersion(serverVersionName, currentVersionName)) {
+                    if (serverVersionCode > currentVersionCode) {
                         activity.runOnUiThread {
                             showUpdateDialog(activity, serverVersionName, changelog, apkUrl)
                         }
@@ -71,29 +78,6 @@ object AppUpdateManager {
         }.start()
     }
 
-    private fun isNewerVersion(server: String, current: String): Boolean {
-        try {
-            // Clean version strings (remove non-numeric suffixes if any)
-            val sClean = server.split("-")[0].split(" ")[0]
-            val cClean = current.split("-")[0].split(" ")[0]
-            
-            val sParts = sClean.split(".").map { it.filter { char -> char.isDigit() }.let { p -> if (p.isEmpty()) 0 else p.toInt() } }
-            val cParts = cClean.split(".").map { it.filter { char -> char.isDigit() }.let { p -> if (p.isEmpty()) 0 else p.toInt() } }
-            
-            val length = Math.max(sParts.size, cParts.size)
-            for (i in 0 until length) {
-                val s = if (i < sParts.size) sParts[i] else 0
-                val c = if (i < cParts.size) cParts[i] else 0
-                if (s > c) return true
-                if (s < c) return false
-            }
-        } catch (e: Exception) {
-            android.util.Log.e("AppUpdateManager", "Version comparison failed: ${e.message}")
-            return false
-        }
-        return false
-    }
-
     private fun showUpdateDialog(activity: Activity, version: String, changelog: String, apkUrl: String) {
         com.google.android.material.dialog.MaterialAlertDialogBuilder(activity)
             .setTitle("새로운 업데이트 발견 (v$version)")