iPhone and iPad app: the same features, served from the Frame

An iPhone can't run Python or ssh, but the Frame can. The app (ios/, SwiftUI)
connects with its own SSH key (Citadel), copies the server and helpers to
~/.cache/frame-control/<version> on the Frame once per version, starts
ui/server.py there with FRAME_LOCAL=1 on the Frame's 127.0.0.1, and shows the
page through an SSH tunnel. The server exits when the phone disconnects.

Server: FRAME_LOCAL=1 puts ui/local-bin on PATH, whose ssh stand-in runs each
`ssh frame COMMAND` locally (and serves as rsync's transport), so desktop and
phone share one code path. Android display goes through podman exec there, as
the Frame has no adb. FRAME_UI_KEY replaces the fixed X-Frame-UI value with a
per-session key. Power actions take the Developer Mode password via sudo -S.
--port 0 now prints the port it took.

Page: a bottom tab bar and safe areas on phones, Play buttons visible on touch
screens, saving through the share sheet, SSH/SFTP/Steam Link/remote desktop
opening in their iOS apps, and a password dialog for power.

App: pairing with the Developer Mode password once (never stored) or with a
key the user adds; host key pinned on first use; plain-language connection
errors with quiet retries; frame-control://install links; alerts and confirms.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ios/FrameControl/Web/WebShell.swift

@@ -0,0 +1,187 @@
+import SwiftUI
+import UIKit
+import WebKit
+
+/// The Frame Control page, served by the server on the headset, in a web view.
+/// window.frameApp (the same bridge the desktop app's preload.js provides) lets
+/// the page use the phone: clipboard, saving images, other apps, install links.
+struct WebShell: UIViewRepresentable {
+    let url: URL
+    @ObservedObject var model: AppModel
+
+    func makeCoordinator() -> Coordinator { Coordinator(model: model) }
+
+    func makeUIView(context: Context) -> WKWebView {
+        let config = WKWebViewConfiguration()
+        let content = WKUserContentController()
+        content.addUserScript(WKUserScript(source: Self.bridge, injectionTime: .atDocumentStart, forMainFrameOnly: true))
+        content.addScriptMessageHandler(context.coordinator, contentWorld: .page, name: "frameApp")
+        config.userContentController = content
+        config.allowsInlineMediaPlayback = true
+        let web = WKWebView(frame: .zero, configuration: config)
+        web.navigationDelegate = context.coordinator
+        web.uiDelegate = context.coordinator
+        web.isOpaque = false
+        web.backgroundColor = UIColor(red: 0.055, green: 0.078, blue: 0.106, alpha: 1)
+        web.scrollView.backgroundColor = web.backgroundColor
+        web.scrollView.contentInsetAdjustmentBehavior = .never  // the page pads for the safe area itself
+        web.allowsBackForwardNavigationGestures = false
+        #if DEBUG
+        web.isInspectable = true
+        #endif
+        context.coordinator.web = web
+        web.load(URLRequest(url: url))
+        return web
+    }
+
+    func updateUIView(_ web: WKWebView, context: Context) {
+        if context.coordinator.loaded != url {
+            context.coordinator.loaded = url
+            web.load(URLRequest(url: url))
+        }
+        context.coordinator.deliverInstallLinks()
+    }
+
+    static let bridge = """
+    (() => {
+      const call = (name, arg) => window.webkit.messageHandlers.frameApp.postMessage({ name, arg: arg ?? null });
+      let installCb = null;
+      window.frameApp = {
+        platform: "ios",
+        readClipboard: () => call("readClipboard"),
+        setUpConnection: () => call("setUpConnection"),
+        open: (what) => call("open", what),
+        saveImages: (images) => call("saveImages", images),
+        onInstallLink: (cb) => { installCb = cb; return call("installLinkReady"); },
+      };
+      window.__frameInstallLink = (req) => { if (installCb) installCb(req); };
+    })();
+    """
+
+    final class Coordinator: NSObject, WKScriptMessageHandlerWithReply, WKNavigationDelegate, WKUIDelegate {
+        let model: AppModel
+        weak var web: WKWebView?
+        var loaded: URL?
+        private var installReady = false
+
+        init(model: AppModel) { self.model = model }
+
+        // MARK: bridge
+
+        @MainActor
+        func userContentController(_ controller: WKUserContentController, didReceive message: WKScriptMessage,
+                                   replyHandler: @escaping (Any?, String?) -> Void) {
+            guard let body = message.body as? [String: Any], let name = body["name"] as? String else {
+                return replyHandler(nil, "bad message")
+            }
+            let arg = body["arg"]
+            switch name {
+            case "readClipboard":
+                replyHandler(UIPasteboard.general.string ?? "", nil)
+            case "setUpConnection":
+                model.showSetup()
+                replyHandler(nil, nil)
+            case "open":
+                let result = open(arg as? String ?? "")
+                replyHandler(result.message.map { ["message": $0] }, result.error)
+            case "saveImages":
+                let images = (arg as? [[String: Any]] ?? []).compactMap { item -> UIImage? in
+                    guard let b64 = item["data"] as? String, let data = Data(base64Encoded: b64) else { return nil }
+                    return UIImage(data: data)
+                }
+                guard !images.isEmpty else { return replyHandler(nil, "No images to save") }
+                share(images)
+                replyHandler(["message": "Choose Save Image to keep \(images.count == 1 ? "it" : "them") in Photos"], nil)
+            case "installLinkReady":
+                installReady = true
+                deliverInstallLinks()
+                replyHandler(nil, nil)
+            default:
+                replyHandler(nil, "unknown request \(name)")
+            }
+        }
+
+        @MainActor
+        func deliverInstallLinks() {
+            guard installReady, let web, !model.pendingInstallLinks.isEmpty else { return }
+            let links = model.pendingInstallLinks
+            model.pendingInstallLinks = []
+            for link in links {
+                let req = ["kind": link.kind.rawValue, "target": link.target]
+                guard let json = try? JSONSerialization.data(withJSONObject: req), let text = String(data: json, encoding: .utf8) else { continue }
+                web.evaluateJavaScript("window.__frameInstallLink(\(text))")
+            }
+        }
+
+        /// SSH, SFTP, Steam Link and remote desktop open in the apps that handle them.
+        @MainActor
+        private func open(_ what: String) -> (message: String?, error: String?) {
+            guard let s = model.settings else { return (nil, "Not paired with a Frame") }
+            let host = s.host.contains(":") ? "[\(s.host)]" : s.host
+            let target: (url: String, app: String, store: String)
+            switch what {
+            case "terminal": target = ("ssh://\(s.user)@\(host):\(s.port)", "an SSH app such as Blink Shell or Termius", "https://apps.apple.com/search?term=ssh")
+            case "sftp": target = ("sftp://\(s.user)@\(host):\(s.port)", "an SFTP app such as Termius or Secure ShellFish", "https://apps.apple.com/search?term=sftp")
+            case "steamlink": target = ("steamlink://", "Steam Link", "https://apps.apple.com/app/steam-link/id1246969117")
+            case "rdp": target = ("rdp://full%20address=s:\(s.host):3389", "Windows App (Microsoft Remote Desktop)", "https://apps.apple.com/app/windows-app/id714464092")
+            default: return (nil, "Can't open \(what) on this \(model.deviceName)")
+            }
+            guard let url = URL(string: target.url) else { return (nil, "Bad address") }
+            if UIApplication.shared.canOpenURL(url) {
+                UIApplication.shared.open(url)
+                return ("Opening \(target.app)", nil)
+            }
+            if let store = URL(string: target.store) { UIApplication.shared.open(store) }
+            return (nil, "Install \(target.app) to open this; opening the App Store")
+        }
+
+        @MainActor
+        private func share(_ images: [UIImage]) {
+            guard let web, let root = web.window?.rootViewController else { return }
+            let sheet = UIActivityViewController(activityItems: images, applicationActivities: nil)
+            sheet.popoverPresentationController?.sourceView = web
+            sheet.popoverPresentationController?.sourceRect = CGRect(x: web.bounds.midX, y: web.bounds.midY, width: 1, height: 1)
+            (root.presentedViewController ?? root).present(sheet, animated: true)
+        }
+
+        // MARK: navigation: the app's page stays here; other sites open in Safari
+
+        func webView(_ webView: WKWebView, decidePolicyFor action: WKNavigationAction,
+                     decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
+            guard let url = action.request.url else { return decisionHandler(.cancel) }
+            if url.host == "127.0.0.1" || url.scheme == "about" || url.scheme == "blob" || url.scheme == "data" {
+                return decisionHandler(.allow)
+            }
+            UIApplication.shared.open(url)
+            decisionHandler(.cancel)
+        }
+
+        func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration,
+                     for action: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
+            if let url = action.request.url { UIApplication.shared.open(url) }  // target="_blank" links
+            return nil
+        }
+
+        // MARK: alert() and confirm(), which the page uses before removing things
+
+        func webView(_ webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String,
+                     initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping () -> Void) {
+            present(message, actions: [UIAlertAction(title: "OK", style: .default) { _ in completionHandler() }], fallback: completionHandler)
+        }
+
+        func webView(_ webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String,
+                     initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (Bool) -> Void) {
+            present(message, actions: [
+                UIAlertAction(title: "Cancel", style: .cancel) { _ in completionHandler(false) },
+                UIAlertAction(title: "OK", style: .default) { _ in completionHandler(true) },
+            ], fallback: { completionHandler(false) })
+        }
+
+        private func present(_ message: String, actions: [UIAlertAction], fallback: @escaping () -> Void) {
+            guard let root = web?.window?.rootViewController else { return fallback() }
+            let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
+            actions.forEach(alert.addAction)
+            (root.presentedViewController ?? root).present(alert, animated: true)
+        }
+    }
+}