fix: share private chat files and harden native lifecycle

Sources/Chat/ChatViews.swift

@@ -133,6 +133,7 @@ struct ChatDetailView: View {
                     Color.clear.frame(height: 1).id("chat-bottom")
                 }.padding(.horizontal, 20).padding(.vertical, 16).frame(maxWidth: 760)
             }
+            .scrollDismissesKeyboard(.interactively)
             .simultaneousGesture(DragGesture().onChanged { _ in follow = false })
             .onChange(of: store.messages) { _, _ in if follow { proxy.scrollTo("chat-bottom", anchor: .bottom) } }
             .overlay(alignment: .bottomTrailing) {
@@ -148,7 +149,7 @@ struct ChatDetailView: View {
                 Button("Talk", systemImage: "waveform") { if let id = store.selected?.id { Task { await talk(id) } } }.disabled(store.activeRun != nil)
                 Button("Export Markdown") { Task { await store.exportConversation(format: "markdown") } }
                 Button("Export JSON") { Task { await store.exportConversation(format: "json") } }
-                if let text = store.exportText { ShareLink("Share export", item: text) }
+                if let file = store.exportFile { ShareLink("Share export file", item: file, preview: SharePreview(file.filename)) }
             } label: { Image(systemName: "ellipsis.circle").frame(minWidth: 44, minHeight: 44) }.accessibilityLabel("Chat actions")
         } }
         .safeAreaInset(edge: .bottom) {
@@ -193,7 +194,15 @@ struct RichChatMarkdown: View {
                     }.padding(12).background(Color(uiColor: .secondarySystemBackground), in: RoundedRectangle(cornerRadius: 12))
                 } else {
                     ForEach(Array(block.text.components(separatedBy: "\n").enumerated()), id: \.offset) { _, line in
-                        if line.hasPrefix("# ") { markdown(String(line.dropFirst(2))).font(.title2.weight(.semibold)) }
+                        if line.trimmingCharacters(in: .whitespaces).hasPrefix("|"), line.contains("|") {
+                            let cells = line.split(separator: "|", omittingEmptySubsequences: true).map { String($0).trimmingCharacters(in: .whitespaces) }
+                            if !cells.allSatisfy({ $0.allSatisfy { "-: ".contains($0) } }) {
+                                HStack(alignment: .top, spacing: 12) { ForEach(Array(cells.enumerated()), id: \.offset) { _, cell in markdown(cell).frame(maxWidth: .infinity, alignment: .leading) } }
+                                    .padding(.vertical, 6).accessibilityElement(children: .combine)
+                                Divider()
+                            }
+                        }
+                        else if line.hasPrefix("# ") { markdown(String(line.dropFirst(2))).font(.title2.weight(.semibold)) }
                         else if line.hasPrefix("## ") { markdown(String(line.dropFirst(3))).font(.title3.weight(.semibold)) }
                         else if line.hasPrefix("### ") { markdown(String(line.dropFirst(4))).font(.headline) }
                         else if line.hasPrefix("- ") || line.hasPrefix("* ") { HStack(alignment: .top) { Text("•"); markdown(String(line.dropFirst(2))) } }