chore: ssh supports modifying the backspace behaviour

src/main/kotlin/app/termora/plugin/internal/ssh/SSHHostOptionsPane.kt

@@ -8,6 +8,7 @@ import app.termora.keymgr.KeyManagerDialog
 import app.termora.plugin.internal.AltKeyModifier
 import app.termora.plugin.internal.BasicProxyOption
 import app.termora.plugin.internal.BasicTerminalOption
+import app.termora.plugin.internal.telnet.TelnetHostOptionsPane.Backspace
 import app.termora.tree.Filter
 import app.termora.tree.HostTreeNode
 import app.termora.tree.NewHostTreeDialog
@@ -36,6 +37,7 @@ internal class SSHHostOptionsPane(private val accountOwner: AccountOwner) : Opti
     private val terminalOption = BasicTerminalOption().apply {
         showCharsetComboBox = true
         showLoginScripts = true
+        showBackspaceComboBox = true
         showEnvironmentTextArea = true
         showStartupCommandTextField = true
         showHeartbeatIntervalTextField = true
@@ -112,6 +114,7 @@ internal class SSHHostOptionsPane(private val accountOwner: AccountOwner) : Opti
             x11Forwarding = tunnelingOption.x11ServerTextField.text,
             loginScripts = terminalOption.loginScripts,
             extras = mutableMapOf(
+                "backspace" to (terminalOption.backspaceComboBox.selectedItem as Backspace).name,
                 "altModifier" to (terminalOption.altModifierComboBox.selectedItem?.toString()
                     ?: AltKeyModifier.EightBit.name),
                 "keywordHighlightSetId" to ((terminalOption.highlightSetComboBox.selectedItem as? KeywordHighlight)?.id
@@ -169,6 +172,9 @@ internal class SSHHostOptionsPane(private val accountOwner: AccountOwner) : Opti
             .getOrNull() ?: AltKeyModifier.EightBit
 
 
+        terminalOption.backspaceComboBox.selectedItem =
+            Backspace.valueOf(host.options.extras["backspace"] ?: Backspace.Delete.name)
+
         val timeout = host.options.extras["timeout"] ?: "60"
         terminalOption.timeoutTextField.value = timeout.toIntOrNull() ?: 60
 

src/main/kotlin/app/termora/plugin/internal/ssh/SSHTerminalTab.kt

@@ -7,9 +7,8 @@ import app.termora.addons.zmodem.ZModemPtyConnectorAdaptor
 import app.termora.database.DatabaseManager
 import app.termora.keymap.KeyShortcut
 import app.termora.keymap.KeymapManager
-import app.termora.terminal.ControlCharacters
+import app.termora.plugin.internal.telnet.TelnetHostOptionsPane
-import app.termora.terminal.DataKey
+import app.termora.terminal.*
-import app.termora.terminal.PtyConnector
 import kotlinx.coroutines.*
 import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.sync.Mutex
@@ -20,6 +19,7 @@ import org.apache.sshd.client.session.ClientSession
 import org.apache.sshd.common.future.CloseFuture
 import org.apache.sshd.common.future.SshFutureListener
 import org.slf4j.LoggerFactory
+import java.awt.event.KeyEvent
 import java.nio.charset.StandardCharsets
 import javax.swing.Icon
 import javax.swing.JComponent
@@ -110,7 +110,18 @@ class SSHTerminalTab(
             // clear screen
             terminal.clearScreen()
             // show cursor
-            terminalModel.setData(DataKey.Companion.ShowCursor, true)
+            terminalModel.setData(DataKey.ShowCursor, true)
+
+            val encoder = terminal.getKeyEncoder()
+            if (encoder is KeyEncoderImpl) {
+                val backspace = host.options.extras["backspace"]
+                if (backspace == TelnetHostOptionsPane.Backspace.Backspace.name) {
+                    encoder.putCode(TerminalKeyEvent(keyCode = KeyEvent.VK_BACK_SPACE), String(byteArrayOf(0x08)))
+                } else if (backspace == TelnetHostOptionsPane.Backspace.VT220.name) {
+                    encoder.putCode(TerminalKeyEvent(keyCode = KeyEvent.VK_BACK_SPACE), "${ControlCharacters.ESC}[3~")
+                }
+            }
+
         }
 
         return ptyConnectorFactory.decorate(