fix(app): render inline links via UITextView span on iOS (#1257)

AssistantMarkdownLink's native branch wrapped its children in a plain RN
<Text>. On iOS that <Text> sits inside the paragraph's native UITextView
and is not hoisted into a UITextViewChild, so link text (markdown links,
bare URLs, and inline-code path links) was silently dropped — the same
root cause as the bold/italic/strikethrough fix in this PR.

Route the native link through MarkdownTextSpan so it composes as a
UITextViewChild and stays visible + selectable. MarkdownTextSpan now
forwards onPress/accessibilityRole across platforms: tappable on
Android/web; on iOS react-native-uitextview nulls onPress on the root
native view, so reliable tap-to-open is still tracked by #21 — but
visible, selectable, copyable link text strictly beats an invisible one.

Refs #1253

Co-authored-by: Geoffrey <geoffrey.marc@consulting-for.edenred.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/app/src/components/markdown-text.android.tsx

@@ -1,18 +1,33 @@
 import { useMemo, type ReactNode } from "react";
-import { Text, View, type StyleProp, type TextStyle, type ViewStyle } from "react-native";
+import {
+  Text,
+  View,
+  type StyleProp,
+  type TextProps,
+  type TextStyle,
+  type ViewStyle,
+} from "react-native";
 
 interface MarkdownTextSpanProps {
   style?: StyleProp<TextStyle>;
   monoSurface?: boolean;
   children: ReactNode;
+  onPress?: TextProps["onPress"];
+  accessibilityRole?: TextProps["accessibilityRole"];
 }
 
 // Android's <Text selectable> enables per-text-node selection natively. Each
 // sibling Text is its own selection scope — drag can't span across siblings
-// (that requires a single UITextView ancestor and is iOS-only).
-export function MarkdownTextSpan({ style, children }: MarkdownTextSpanProps) {
+// (that requires a single UITextView ancestor and is iOS-only). onPress works
+// natively here, so links routed through this span stay tappable on Android.
+export function MarkdownTextSpan({
+  style,
+  children,
+  onPress,
+  accessibilityRole,
+}: MarkdownTextSpanProps) {
   return (
-    <Text selectable style={style}>
+    <Text selectable style={style} onPress={onPress} accessibilityRole={accessibilityRole}>
       {children}
     </Text>
   );