fix(auth): auto-submit filled keyboard-interactive prompts

[RoryChou-flux]

Summary

• Auto-fill password-like keyboard-interactive prompts from saved password.
• Auto-submit keyboard-interactive requests when all prompts are already filled (prevents modal flash).
• Prefer keyboard-interactive before password in password-only auth flows to avoid duplicate OTP challenges.

Behavior Notes

• No behavior change for key-only or agent-first flows.
• Keyboard-interactive remains a fallback for non-password-only paths.

Validation

• npm run -s lint -- components/KeyboardInteractiveModal.tsx
• node --check electron/bridges/sshAuthHelper.cjs

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Keep password before keyboard-interactive for MFA handshakes

In buildAuthHandler's password-only dynamic branch, putting keyboard-interactive before password breaks ordered MFA flows when fallback options are present (for example, OpenSSH AuthenticationMethods password,keyboard-interactive). The auth loop marks each method as attempted before checking methodsLeft, so an initial round with only password available consumes keyboard-interactive without sending it; after password succeeds with partial auth, the next round can no longer select keyboard-interactive and authentication fails.

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