fix(shift): add color legend and restore manifest trailing newline

- Add legend text (班/休/断点 color meanings) below mini calendar
- Restore trailing newline in AndroidManifest.xml

app/src/main/AndroidManifest.xml

@@ -54,4 +54,4 @@
             android:exported="false" />
     </application>
 
-</manifest>
+</manifest>

core/src/main/kotlin/plus/rua/project/ui/ShiftPatternScreen.kt

@@ -160,6 +160,11 @@ fun ShiftPatternScreen(onBack: () -> Unit) {
                 style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant
             )
+            Text(
+                text = "图例:班(蓝)/休(红)/断点(琥珀)",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant
+            )
 
             OutlinedButton(
                 onClick = { showResetDialog = true },