P3 Stream L: widget refresh scheduler (WorkManager, iOS cadence)

WidgetRefreshSchedule: 30-min day / 120-min overnight (6am–11pm split).
WidgetRefreshWorker: CoroutineWorker fetches via APILayer -> repo -> widget.update.
WidgetUpdateManager: chained one-time enqueue pattern (WorkManager PeriodicWork
can't vary cadence).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composeApp/build.gradle.kts

@@ -69,6 +69,9 @@ kotlin {
             // DataStore for widget data persistence
             implementation("androidx.datastore:datastore-preferences:1.1.1")
 
+            // WorkManager for scheduled widget refresh (iOS parity — Stream L)
+            implementation("androidx.work:work-runtime-ktx:2.9.1")
+
             // Encrypted SharedPreferences for secure token storage
             implementation(libs.androidx.security.crypto)
 
@@ -126,6 +129,7 @@ kotlin {
                 implementation(libs.androidx.test.core)
                 implementation(libs.androidx.test.core.ktx)
                 implementation(libs.androidx.testExt.junit)
+                implementation("androidx.work:work-testing:2.9.1")
             }
         }
         val androidInstrumentedTest by getting {