fix: implement proper text selection using UITextView

Replaced SwiftUI Text with UITextView wrapper to enable full text selection
and copy/paste functionality. The previous .textSelection(.enabled) modifier
didn't work reliably, especially with custom URL handlers.

Changes:
- Created SelectableTextView using UIViewRepresentable
- Wrapped UITextView with isSelectable=true, isEditable=false
- Maintained all styling (font size, line spacing)
- Preserved link tap handling through UITextViewDelegate
- Now supports native iOS text selection gestures and copy/paste

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: graycreate

V2er/Sources/RichView/Views/RichView.swift

@@ -66,14 +66,12 @@ public struct RichView: View {
             } else if let error = error {
                 ErrorView(error: error)
             } else if let attributedString = attributedString {
-                Text(attributedString)
-                    .font(.system(size: configuration.stylesheet.body.fontSize))
-                    .lineSpacing(configuration.stylesheet.body.lineSpacing)
-                    .textSelection(.enabled)
-                    .environment(\.openURL, OpenURLAction { url in
-                        onLinkTapped?(url)
-                        return .handled
-                    })
+                SelectableTextView(
+                    attributedString: attributedString,
+                    fontSize: configuration.stylesheet.body.fontSize,
+                    lineSpacing: configuration.stylesheet.body.lineSpacing,
+                    onLinkTapped: onLinkTapped
+                )
             } else {
                 Text("No content")
                     .foregroundColor(.secondary)
@@ -248,4 +246,70 @@ public struct RenderMetadata {
 
     /// Number of @mentions in the content
     public let mentionCount: Int
+}
+
+// MARK: - Selectable Text View
+
+/// A UIViewRepresentable wrapper for UITextView that supports text selection
+@available(iOS 18.0, *)
+struct SelectableTextView: UIViewRepresentable {
+    let attributedString: AttributedString
+    let fontSize: CGFloat
+    let lineSpacing: CGFloat
+    let onLinkTapped: ((URL) -> Void)?
+
+    func makeUIView(context: Context) -> UITextView {
+        let textView = UITextView()
+        textView.isEditable = false
+        textView.isSelectable = true
+        textView.isScrollEnabled = false
+        textView.backgroundColor = .clear
+        textView.textContainerInset = .zero
+        textView.textContainer.lineFragmentPadding = 0
+        textView.delegate = context.coordinator
+        textView.dataDetectorTypes = []
+        textView.linkTextAttributes = [
+            .foregroundColor: UIColor.systemBlue,
+            .underlineStyle: NSUnderlineStyle.single.rawValue
+        ]
+        return textView
+    }
+
+    func updateUIView(_ textView: UITextView, context: Context) {
+        // Convert AttributedString to NSAttributedString
+        var nsAttributedString = NSAttributedString(attributedString)
+
+        // Apply line spacing
+        let paragraphStyle = NSMutableParagraphStyle()
+        paragraphStyle.lineSpacing = lineSpacing
+
+        let mutableAttributedString = NSMutableAttributedString(attributedString: nsAttributedString)
+        mutableAttributedString.addAttribute(
+            .paragraphStyle,
+            value: paragraphStyle,
+            range: NSRange(location: 0, length: mutableAttributedString.length)
+        )
+
+        textView.attributedText = mutableAttributedString
+    }
+
+    func makeCoordinator() -> Coordinator {
+        Coordinator(onLinkTapped: onLinkTapped)
+    }
+
+    class Coordinator: NSObject, UITextViewDelegate {
+        let onLinkTapped: ((URL) -> Void)?
+
+        init(onLinkTapped: ((URL) -> Void)?) {
+            self.onLinkTapped = onLinkTapped
+        }
+
+        func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {
+            if interaction == .invokeDefaultAction {
+                onLinkTapped?(URL)
+                return false
+            }
+            return true
+        }
+    }
 }