fix(app): stop markdown lines joining

Custom line-break rules dropped the resolved full-width break style, allowing adjacent native text spans to collapse onto one line. Preserve the break styles in both chat and shared Markdown renderers.

packages/app/src/components/markdown/renderer.tsx

@@ -569,8 +569,26 @@ export function createSharedMarkdownRules(): RenderRules {
         {children}
       </MarkdownInheritedText>
     ),
-    hardbreak: (node: ASTNode) => <MarkdownTextSpan key={node.key}>{"\n"}</MarkdownTextSpan>,
-    softbreak: (node: ASTNode) => <MarkdownTextSpan key={node.key}>{"\n"}</MarkdownTextSpan>,
+    hardbreak: (
+      node: ASTNode,
+      _children: ReactNode[],
+      _parent: ASTNode[],
+      styles: MarkdownStyles,
+    ) => (
+      <MarkdownTextSpan key={node.key} style={styles.hardbreak}>
+        {"\n"}
+      </MarkdownTextSpan>
+    ),
+    softbreak: (
+      node: ASTNode,
+      _children: ReactNode[],
+      _parent: ASTNode[],
+      styles: MarkdownStyles,
+    ) => (
+      <MarkdownTextSpan key={node.key} style={styles.softbreak}>
+        {"\n"}
+      </MarkdownTextSpan>
+    ),
     code_block: (
       node: ASTNode,
       _children: ReactNode[],

packages/app/src/components/message.tsx

@@ -1689,10 +1689,29 @@ export const AssistantMessage = memo(function AssistantMessage({
       // plain <Text> is not hoisted into a UITextViewChild and is dropped (same
       // root cause as strong/em/s) — so on iOS a hard line break vanished, and
       // a softbreak between words jammed them together ("one\ntwo" -> "onetwo").
-      // Emit the break through MarkdownTextSpan so it composes on iOS; web and
-      // Android keep the same "\n" they rendered before.
-      hardbreak: (node: ASTNode) => <MarkdownTextSpan key={node.key}>{"\n"}</MarkdownTextSpan>,
-      softbreak: (node: ASTNode) => <MarkdownTextSpan key={node.key}>{"\n"}</MarkdownTextSpan>,
+      // Emit the break through MarkdownTextSpan so it composes on iOS. Keep
+      // the resolved break styles: hardbreak is a full-width flex-row child on
+      // Android, and dropping that width joins the surrounding text spans.
+      hardbreak: (
+        node: ASTNode,
+        _children: ReactNode[],
+        _parent: ASTNode[],
+        styles: MarkdownStyles,
+      ) => (
+        <MarkdownTextSpan key={node.key} style={styles.hardbreak}>
+          {"\n"}
+        </MarkdownTextSpan>
+      ),
+      softbreak: (
+        node: ASTNode,
+        _children: ReactNode[],
+        _parent: ASTNode[],
+        styles: MarkdownStyles,
+      ) => (
+        <MarkdownTextSpan key={node.key} style={styles.softbreak}>
+          {"\n"}
+        </MarkdownTextSpan>
+      ),
       code_block: (
         node: ASTNode,
         _children: ReactNode[],