SFTP on iPhone and iPad, done right

Reading and writing files on a remote server from an iPhone is harder than it should be, most workflows end up with copy-paste through an SSH terminal, or a web-based file manager open in a tab. SSHive ships a real native SFTP client on iOS and iPadOS: a remote file browser, a transfer queue with real-time progress, a built-in text editor for in-place edits, and integration with the iOS Files app so you can drop something from iCloud Drive straight onto a server. Credentials and host keys live in the Keychain behind Face ID or Touch ID, same security model as the SSH terminal. Free covers 10 MB per file (enough for most configs, scripts and small assets), Pro unlocks unlimited transfer size and adds session logging and `.sshive` profile export/import. Universal Purchase: pay once for Pro on the App Store, use it across iPhone, iPad and Mac. No subscription, no data sent to us, and if you hit a use case the editor or browser does not cover well, tell us, we listen.

SFTP on iOS has two non-obvious challenges. First, the iOS sandbox: every app has its own private container, and the Files app sandbox is even stricter, you cannot just `open()` a file from another app the way you would on a desktop. SSHive uses the iOS document picker, the share sheet, and Universal Type Identifiers (UTIs) to bridge the gap, registering itself as a destination so other apps can hand off files for upload, and exporting downloads back through the share sheet or directly into Files. Second, the network model: an SFTP transfer is a long-lived TCP connection to a remote SSH server, and iOS will suspend or kill background apps to save power. SSHive uses `URLSession`-backed background transfers for large files (so a 200 MB download survives the user switching apps), and breaks the SFTP transfer queue into 4 parallel streams to maximize throughput on cellular and high-latency links, the same chunked-parallel pattern the macOS version uses. The credential model deserves attention too. The remote SSH server might require a password, a private key, a passphrase-protected private key, or a jump host that adds another credential. SSHive's SFTP reuses the SSH profile's credentials directly, one profile, one set of credentials, used for both terminal and SFTP. The Keychain entry has `kSecAttrAccessibleWhenUnlockedThisDeviceOnly`, meaning if your iPhone is locked, the credentials are inaccessible even to SSHive itself; once unlocked with Face ID / Touch ID, they become available to the running session. This balances usability with the security expectation that secrets cannot be exfiltrated by a thief who steals the phone.