feat(ssh): pre-populate vault password in auth prompts for MFA (fixes #9911) (#11170)

* feat(ssh): pre-populate vault password in auth prompts for MFA use cases

When a keyboard-interactive password prompt is shown and the response
field is empty, load and pre-fill the saved vault password. This lets
users with hardware tokens (e.g. YubiKey) press their token to append
a TOTP to the pre-filled base password without re-typing it.

Also pre-fill the prompt-password modal with the vault password so the
same workflow applies when SSH password auth is used with MFA.

Closes #9911

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(ssh): remove unnecessary null coalescing in loadPassword call

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

tabby-ssh/src/components/keyboardInteractiveAuthPanel.component.ts

@@ -1,4 +1,4 @@
-import { Component, Input, Output, EventEmitter, ViewChild, ElementRef, ChangeDetectionStrategy } from '@angular/core'
+import { Component, Input, Output, EventEmitter, ViewChild, ElementRef, ChangeDetectionStrategy, OnInit, ChangeDetectorRef } from '@angular/core'
 import { KeyboardInteractivePrompt } from '../session/ssh'
 import { SSHProfile } from '../api'
 import { PasswordStorageService } from '../services/passwordStorage.service'
@@ -9,7 +9,7 @@ import { PasswordStorageService } from '../services/passwordStorage.service'
     styleUrls: ['./keyboardInteractiveAuthPanel.component.scss'],
     changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class KeyboardInteractiveAuthComponent {
+export class KeyboardInteractiveAuthComponent implements OnInit {
     @Input() profile: SSHProfile
     @Input() prompt: KeyboardInteractivePrompt
     @Input() step = 0
@@ -17,7 +17,22 @@ export class KeyboardInteractiveAuthComponent {
     @ViewChild('input') input: ElementRef
     remember = false
 
-    constructor (private passwordStorage: PasswordStorageService) {}
+    constructor (
+        private passwordStorage: PasswordStorageService,
+        private cdr: ChangeDetectorRef,
+    ) {}
+
+    async ngOnInit (): Promise<void> {
+        const savedPassword = await this.passwordStorage.loadPassword(this.profile)
+        if (savedPassword) {
+            for (let i = 0; i < this.prompt.prompts.length; i++) {
+                if (this.prompt.isAPasswordPrompt(i) && !this.prompt.responses[i]) {
+                    this.prompt.responses[i] = savedPassword
+                }
+            }
+            this.cdr.markForCheck()
+        }
+    }
 
     isPassword (): boolean {
         return this.prompt.isAPasswordPrompt(this.step)

tabby-ssh/src/session/ssh.ts

@@ -657,6 +657,10 @@ export class SSHSession {
                 modal.componentInstance.prompt = `Password for ${this.authUsername}@${this.profile.options.host}`
                 modal.componentInstance.password = true
                 modal.componentInstance.showRememberCheckbox = true
+                const prefilledPassword = await this.passwordStorage.loadPassword(this.profile, this.authUsername)
+                if (prefilledPassword) {
+                    modal.componentInstance.value = prefilledPassword
+                }
 
                 try {
                     const promptResult = await modal.result.catch(() => null)