fix(gui): honest key setup outcomes, quit confirmation, streamer mode leaks

CHANGELOG.md

@@ -15,6 +15,7 @@ Versions follow [Semantic Versioning](https://semver.org/).
 - **Drag files and folders between the SFTP panes, or onto the remote pane from your file manager.** In the desktop app, dragging a row to the other pane uploads or downloads it into the folder row it is dropped on, or else into the folder on show, and dragging a ticked row takes every ticked row along. Files and folders dropped from Explorer, Finder or a Linux file manager onto the remote pane upload to it. Escape cancels a drag.
 - **Both apps transfer whole folders.** Upload and Download in the desktop app, and copy and paste in the terminal app, take a folder with everything in it, merge it into a folder of the same name and replace files that clash, and the desktop app asks first when the folder on show already has those names. Files and folders keep their permission bits, so scripts stay executable, and a copy stays writable for you so the next transfer can replace it; symbolic links and special files are skipped, and the transfer ends by saying how many items were skipped or failed and why the first one was. Cancel in the desktop app's progress strip, closing its tab, or Esc in the terminal app stops a transfer and removes the file it was part way through.
 - **The file panes show when each file was last changed.** The desktop app's panes gain a Modified column, with the full date and time on hover, once the window is wide enough. The terminal app's file manager shows the time at the end of each row when its panel is wide enough.
+- **Streamer mode shows when it is on and switches from anywhere.** In the desktop app it could only be switched in Settings, and nothing on screen said it was on. While it is on, an eye in the status bar says so. `⌘⇧S` on macOS or `Ctrl+Shift+S` elsewhere and "Toggle streamer mode" in the command palette switch it from any screen, a terminal included.
 
 ### Bug Fixes
 - **Security: a server that offers a host key of another type than the one saved for it is refused.** OmnySSH compared the offered key only with saved keys of the same type. A host saved with its Ed25519 key that suddenly offered only an RSA or ECDSA key was therefore taken for a new host: the key was saved and the login went ahead, password included, and the dashboard did this in the background without anyone connecting. Someone intercepting the connection could get past the saved key this way. Like `ssh`, OmnySSH now refuses any key that matches none of those saved for the host, whatever its type, and says which type is saved. A server that really dropped the type of key it was saved with needs its old key removed once, as `ssh` also asks.
@@ -33,6 +34,11 @@ Versions follow [Semantic Versioning](https://semver.org/).
 - **Pasting a folder in the terminal app copies it instead of leaving an empty file.** The file manager handed a folder to the transfer as if it were a file, so the paste failed after creating an empty file of that name on the other side.
 - **A paste or delete of more than 64 items in the terminal app handles them all.** They went to the SFTP queue at once, and whatever did not fit in its 64 places was dropped without a word while the app kept waiting for it. They now go one at a time.
 - **The terminal app no longer crashes when a file grows while it is copied.** A log still being written to could end up larger than when its transfer started, which took the progress bar past 100% and brought the app down.
+- **Key setup no longer reports success while the server still takes passwords.** Turning password login off needs sudo without a password prompt. Without it, as for an account whose sudo asks for a password, key setup stopped once the new key worked, yet the desktop app said "Key authentication configured", the card showed a key badge and the key button was gone, so there was no way to try again. The terminal app went further: it marked the host key-only and deleted the saved password. Both apps now say that key login works and password login is still on, and keep the saved password. The desktop app's card shows a "Password on" badge that runs the setup again, for when sudo allows it, and a shield for a host that takes keys only. After a full setup it also says that the server's SSH settings were changed, where their backup is, and that the saved password was removed.
+- **The desktop app asks before setting up a key.** One click on the key icon generated a key, added it to the server and could turn password login off for every account on it. A dialog now says what will happen and names the key file, and nothing starts until you confirm. Cancel is focused, and Esc or a click outside cancels.
+- **Key setup that fails after turning password login off says so.** When the last check failed, the desktop app said "Password authentication was not changed", although password login had been turned off, and even when turning it back on failed and left the server reachable only through the hosting provider's console. It now says when password login was turned back on, and when it may still be off, now or after the SSH service restarts: then it keeps the new key for the host, says how to check the server's setting and restore its backup, and offers a terminal to do it.
+- **The desktop app asks before quitting while anything is still open.** Closing the window, `⌘Q`, the tray's Quit, and `⌘W` on macOS ended every terminal, transfer, tunnel and snippet run without a word. Closing or quitting now asks first and names what will be closed, with a "Don't ask again" box; Settings → Window turns the question back on. On macOS `⌘W` closes the active tab and `⌘⇧W` the window. Quitting from the Dock or by logging out still does not ask.
+- **Streamer mode hides addresses in error messages and the host form too.** The cards showed made-up addresses, but the status bar printed real ones, for example for a changed host key or a tunnel that could not open, and so did the file panes, snippet results and key setup. Errors now show the same made-up addresses as the cards, and the host form hides its addresses until you click Reveal.
 
 ---
 

crates/omnyssh-core/src/event.rs

@@ -149,6 +149,12 @@ pub enum CoreEvent {
     KeySetupFailed(HostId, String),
     /// Emergency rollback was triggered (host_id, rollback_result).
     KeySetupRollback(HostId, String),
+    /// Key login works, but password login stayed on: changing the server's
+    /// settings needs sudo without a password (host_id, private_key_path).
+    KeySetupPartial(HostId, std::path::PathBuf),
+    /// Key setup failed and the server's password login may be off: the
+    /// rollback failed or the disable step never answered (host_id, error_message).
+    KeySetupFailedUnsafe(HostId, String),
 
     /// A private key is encrypted and no passphrase is cached for it yet.
     /// Frontends prompt once per key path and call [`crate::ssh::identity::unlock`].