ios: file/image UI — mirror the Mac (inline preview, attach to send)

Wire on_file into the iOS app: received files save to Documents; images render
inline in the feed, other files show a doc chip. A paperclip opens a file
importer → send_file. FeedItem gains optional image/fileURL, matching macOS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ios/TetherApp/Sources/RoomView.swift

@@ -1,8 +1,10 @@
 import SwiftUI
+import UniformTypeIdentifiers
 
 struct RoomView: View {
     @Bindable var store: TetherStore
     @State private var draft = ""
+    @State private var showImporter = false
 
     var body: some View {
         NavigationStack {
@@ -134,19 +136,29 @@ struct RoomView: View {
     private var feedList: some View {
         List(store.feed) { msg in
             VStack(alignment: .leading, spacing: 4) {
-                Text(msg.text ?? "")
-                    .lineLimit(4)
+                if let image = msg.image {
+                    Image(uiImage: image)
+                        .resizable().scaledToFit()
+                        .frame(maxHeight: 220)
+                        .clipShape(RoundedRectangle(cornerRadius: 6))
+                } else if msg.isFile {
+                    Label(msg.text, systemImage: "doc.fill").lineLimit(1)
+                } else {
+                    Text(msg.text).lineLimit(4)
+                }
                 HStack {
-                    Text(msg.source ?? "?").font(.caption2)
+                    Text(msg.isFile ? "file" : msg.source).font(.caption2)
                     Spacer()
                     Text(msg.date, style: .time).font(.caption2)
                 }
                 .foregroundStyle(.secondary)
             }
             .contentShape(Rectangle())
-            .onTapGesture { store.copyToPasteboard(msg) }
+            .onTapGesture { if !msg.isFile { store.copyToPasteboard(msg) } }
             .swipeActions {
-                Button("Copy") { store.copyToPasteboard(msg) }.tint(.blue)
+                if !msg.isFile {
+                    Button("Copy") { store.copyToPasteboard(msg) }.tint(.blue)
+                }
             }
         }
         .listStyle(.plain)
@@ -161,6 +173,13 @@ struct RoomView: View {
 
     private var composer: some View {
         HStack {
+            Button { showImporter = true } label: {
+                Image(systemName: "paperclip").font(.title2)
+            }
+            .disabled(!store.connected)
+            .fileImporter(isPresented: $showImporter, allowedContentTypes: [.item]) { result in
+                if case .success(let url) = result { store.sendFile(at: url) }
+            }
             TextField("Type or paste…", text: $draft, axis: .vertical)
                 .textFieldStyle(.roundedBorder)
                 .lineLimit(1...4)

ios/TetherApp/Sources/TetherStore.swift

@@ -8,11 +8,14 @@ import enum TetherKit.RoomIdentity   // selective: avoids TetherKit.Message clas
 
 /// UI-facing clipboard item. Decouples the view from the FFI `Message` record
 /// and supplies the `id`/`date` SwiftUI's List needs.
-struct FeedItem: Identifiable, Equatable {
+struct FeedItem: Identifiable {
     let id = UUID()
-    let text: String
+    let text: String        // clipboard text, or the file name for files
     let source: String
     let date: Date
+    var image: UIImage? = nil  // preview for image files
+    var fileURL: URL? = nil    // saved location for any received file
+    var isFile: Bool { fileURL != nil }
 }
 
 /// Observable bridge between the shared `tethercore.Engine` and SwiftUI.
@@ -105,6 +108,39 @@ final class TetherStore {
         engine?.send(text: text)
     }
 
+    /// Send a picked file P2P.
+    func sendFile(at url: URL) {
+        let scoped = url.startAccessingSecurityScopedResource()
+        defer { if scoped { url.stopAccessingSecurityScopedResource() } }
+        guard let data = try? Data(contentsOf: url) else { return }
+        engine?.sendFile(name: url.lastPathComponent, mime: Self.mime(for: url.pathExtension), data: data)
+    }
+
+    static func mime(for ext: String) -> String {
+        switch ext.lowercased() {
+        case "png": return "image/png"
+        case "jpg", "jpeg": return "image/jpeg"
+        case "gif": return "image/gif"
+        case "heic": return "image/heic"
+        case "pdf": return "application/pdf"
+        case "txt": return "text/plain"
+        default: return "application/octet-stream"
+        }
+    }
+
+    /// A received file: save to Documents, preview if it's an image.
+    fileprivate func ingestFile(name: String, mime: String, data: Data, date: Date) {
+        let image: UIImage? = mime.hasPrefix("image/") ? UIImage(data: data) : nil
+        var url: URL?
+        if let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
+            let dest = docs.appendingPathComponent(name.isEmpty ? "tether-file" : name)
+            try? data.write(to: dest)
+            url = dest
+        }
+        feed.insert(FeedItem(text: name, source: "file", date: date, image: image, fileURL: url), at: 0)
+        if feed.count > 100 { feed.removeLast() }
+    }
+
     /// Copy a received message back onto the local pasteboard.
     func copyToPasteboard(_ item: FeedItem) {
         UIPasteboard.general.string = item.text
@@ -143,6 +179,6 @@ private final class EngineBridge: MessageHandler {
     }
 
     func onFile(name: String, mime: String, data: Data) {
-        // File receive UI is a follow-up; engine handles transport + reassembly.
+        Task { @MainActor in self.store?.ingestFile(name: name, mime: mime, data: data, date: Date()) }
     }
 }