feat(ssh): auto-fill ssh config parameters in auth form

Resolve SSH host parameters in auth forms and CLI connections while preserving explicit user, bookmark, and parsed alias values. Continue forwarding SSH config files for HostName and other SSH options, and document the precedence in English and Chinese.

Closes #441

src/ui/activities/auth.rs

@@ -243,6 +243,18 @@ enum FormTab {
 const STORE_KEY_LATEST_VERSION: &str = "AUTH_LATEST_VERSION";
 const STORE_KEY_RELEASE_NOTES: &str = "AUTH_RELEASE_NOTES";
 
+fn should_resolve_ssh_host_params(
+    protocol: FileTransferProtocol,
+    mounted_address: &str,
+    address: &str,
+    force: bool,
+) -> bool {
+    matches!(
+        protocol,
+        FileTransferProtocol::Scp | FileTransferProtocol::Sftp
+    ) && (force || mounted_address != address)
+}
+
 /// AuthActivity is the data holder for the authentication activity
 pub struct AuthActivity {
     app: Application<Id, Msg, NoUserEvent>,
@@ -256,7 +268,11 @@ pub struct AuthActivity {
     redraw: bool,
     /// Host bridge protocol
     host_bridge_protocol: HostBridgeProtocol,
+    /// Last Host address applied to the Host Bridge form.
+    last_host_bridge_address: String,
     last_form_tab: FormTab,
+    /// Last Host address applied to the Remote form.
+    last_remote_address: String,
     /// Remote file transfer protocol
     remote_protocol: FileTransferProtocol,
     context: Option<Context>,
@@ -273,6 +289,8 @@ impl AuthActivity {
             bookmarks_list: Vec::new(),
             exit_reason: None,
             last_form_tab: FormTab::Remote,
+            last_host_bridge_address: String::new(),
+            last_remote_address: String::new(),
             recents_list: Vec::new(),
             redraw: true,
             host_bridge_protocol: HostBridgeProtocol::Localhost,
@@ -317,6 +335,20 @@ impl AuthActivity {
         self.remote_protocol = protocol;
     }
 
+    fn last_mounted_address(&self, form_tab: FormTab) -> &str {
+        match form_tab {
+            FormTab::HostBridge => self.last_host_bridge_address.as_str(),
+            FormTab::Remote => self.last_remote_address.as_str(),
+        }
+    }
+
+    fn set_last_mounted_address(&mut self, form_tab: FormTab, address: &str) {
+        match form_tab {
+            FormTab::HostBridge => self.last_host_bridge_address = address.to_string(),
+            FormTab::Remote => self.last_remote_address = address.to_string(),
+        }
+    }
+
     /// Get current input mask to show
     fn host_bridge_input_mask(&self) -> InputMask {
         match self.host_bridge_protocol {
@@ -444,4 +476,61 @@ mod tests {
             FileTransferProtocol::GoogleCloudStorage
         );
     }
+
+    #[test]
+    fn should_resolve_ssh_params_only_after_host_change_or_forced_ssh_transition() {
+        assert!(should_resolve_ssh_host_params(
+            FileTransferProtocol::Sftp,
+            "saved-host",
+            "edited-host",
+            false
+        ));
+        assert!(!should_resolve_ssh_host_params(
+            FileTransferProtocol::Sftp,
+            "saved-host",
+            "saved-host",
+            false
+        ));
+        assert!(should_resolve_ssh_host_params(
+            FileTransferProtocol::Scp,
+            "saved-host",
+            "saved-host",
+            true
+        ));
+        assert!(!should_resolve_ssh_host_params(
+            FileTransferProtocol::Ftp(false),
+            "saved-host",
+            "edited-host",
+            true
+        ));
+    }
+
+    #[test]
+    fn should_track_host_bridge_and_remote_addresses_independently() {
+        let mut activity = AuthActivity::new(Duration::ZERO);
+
+        activity.set_last_mounted_address(FormTab::HostBridge, "bookmark-host");
+        activity.set_last_mounted_address(FormTab::Remote, "recent-host");
+
+        assert_eq!(
+            activity.last_mounted_address(FormTab::HostBridge),
+            "bookmark-host"
+        );
+        assert_eq!(
+            activity.last_mounted_address(FormTab::Remote),
+            "recent-host"
+        );
+        assert!(!should_resolve_ssh_host_params(
+            FileTransferProtocol::Sftp,
+            activity.last_mounted_address(FormTab::Remote),
+            "recent-host",
+            false
+        ));
+        assert!(should_resolve_ssh_host_params(
+            FileTransferProtocol::Sftp,
+            activity.last_mounted_address(FormTab::HostBridge),
+            "edited-host",
+            false
+        ));
+    }
 }