fix(ui): clear text selection on tap anywhere in the article

Every block of the dictionary article was wrapped in its own
SelectionContainer, so a tap in one block never cleared a highlight
held in another. A single container now wraps the article list — a tap
anywhere clears the selection and selection can span adjacent blocks.

app/src/main/java/com/example/research/ui/article/ArticleScreen.kt

@@ -123,59 +123,63 @@ fun ArticleContent(
             val isHeavyArticle =
                 articleState.dslContent.size > HEAVY_ARTICLE_BLOCK_COUNT
 
-            LazyColumn(
+            val articleList: @Composable (Modifier) -> Unit = { listModifier ->
-                state = listState,
+                LazyColumn(
-                contentPadding = PaddingValues(top = Spacing.listItemVertical),
+                    state = listState,
-                modifier = modifier
+                    contentPadding = PaddingValues(top = Spacing.listItemVertical),
-                    .fillMaxSize()
+                    modifier = listModifier
-                    .onSizeChanged { viewportSize = it }
+                        .testTag("article_content")
-                    .windowInsetsPadding(AppWindowInsets.horizontalSafeDrawing)
+                        .semantics {
-                    .padding(end = 16.dp)
+                            testTagsAsResourceId = true
-                    .testTag("article_content")
+                        }
-                    .semantics {
+                ) {
-                        testTagsAsResourceId = true
+                    itemsIndexed(
-                    }
+                        items = articleState.dslContent,
-            ) {
+                        key = { index, _ ->
-                itemsIndexed(
+                            // Use stable key combining article save key and index
-                    items = articleState.dslContent,
+                            "$articleSaveKey:$index"
-                    key = { index, _ ->
+                        },
-                        // Use stable key combining article save key and index
+                        contentType = { _, _ -> "article_block" }
-                        "$articleSaveKey:$index"
+                    ) { index, block ->
-                    },
+                        val followedByContinuation =
-                    contentType = { _, _ -> "article_block" }
+                            articleState.dslContent.getOrNull(index + 1)?.continuesPrevious == true
-                ) { index, block ->
+                        val textContent = @Composable {
-                    val followedByContinuation =
+                            Box(
-                        articleState.dslContent.getOrNull(index + 1)?.continuesPrevious == true
+                                modifier = Modifier
-                    val textContent = @Composable {
+                                    .padding(
-                        Box(
+                                        start = Spacing.contentStart + indentStep * block.indent
-                            modifier = Modifier
+                                    )
-                                .padding(
+                                    .padding(bottom = if (followedByContinuation) 0.dp else 8.dp)
-                                    start = Spacing.contentStart + indentStep * block.indent
+                            ) {
+                                ArticleLinkText(
+                                    block = block,
+                                    linksEnabled = true,
+                                    preferDirectHitTesting = isHeavyArticle,
+                                    style = baseTextStyle,
+                                    onRefClick = refClickHandler,
+                                    onTextLayout = {},
+                                    modifier = Modifier
+                                        .testTag("article_block_$index")
+                                        .semantics {
+                                            testTagsAsResourceId = true
+                                        }
                                 )
-                                .padding(bottom = if (followedByContinuation) 0.dp else 8.dp)
+                            }
-                        ) {
-                            ArticleLinkText(
-                                block = block,
-                                linksEnabled = true,
-                                preferDirectHitTesting = isHeavyArticle,
-                                style = baseTextStyle,
-                                onRefClick = refClickHandler,
-                                onTextLayout = {},
-                                modifier = Modifier
-                                    .testTag("article_block_$index")
-                                    .semantics {
-                                        testTagsAsResourceId = true
-                                    }
-                            )
                         }
-                    }
-                    if (isHeavyArticle) {
                         textContent()
-                    } else {
-                        SelectionContainer { textContent() }
                     }
                 }
             }
+            val articleListModifier = modifier
+                .fillMaxSize()
+                .onSizeChanged { viewportSize = it }
+                .windowInsetsPadding(AppWindowInsets.horizontalSafeDrawing)
+                .padding(end = 16.dp)
+            if (isHeavyArticle) {
+                articleList(articleListModifier)
+            } else {
+                SelectionContainer { articleList(articleListModifier) }
+            }
         }
         is ArticleState.Error -> {
             Column(