bug: kiro cli agent is not accessible

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

Linux 4.18.0-553.105.1.el8_10.x86_64 - Red Hat Enterprise Linux 8.10 (Ootpa)

### Expected behaviour

kiro-cli version: 1.28.0

Problem: CLI hangs after MCP warning, never shows input prompt

Works with: --tui flag (but very slow)

Doesn't work with: default UI and --legacy-ui

kiro-cli doctor output: sshd config: Could not read sshd_config — missing AcceptEnv Q_SET_PARENT and AllowStreamLocalForwarding yes

Verbose log shows: All API calls succeed (GetProfile, ListAvailableModels, telemetry) — hangs after initialization when rendering the UI

Environment: SSH session to remote Linux server, no root access to modify sshd_config

Started after: laptop restart, was working before with same setup

Debug log location: /tmp/kiro-debug.log

The main ask should be: the CLI should either fall back gracefully to a working UI when sshd features are unavailable, or show a clear error message instead of silently hanging.

### Actual behaviour

agent is in hang state and not able to login to cli.

### Steps to reproduce

kiro-cli version: 1.28.0

Problem: CLI hangs after MCP warning, never shows input prompt

Works with: --tui flag (but very slow)

Doesn't work with: default UI and --legacy-ui

kiro-cli doctor output: sshd config: Could not read sshd_config — missing AcceptEnv Q_SET_PARENT and AllowStreamLocalForwarding yes

Verbose log shows: All API calls succeed (GetProfile, ListAvailableModels, telemetry) — hangs after initialization when rendering the UI

Environment: SSH session to remote Linux server, no root access to modify sshd_config

Started after: laptop restart, was working before with same setup

Debug log location: /tmp/kiro-debug.log

The main ask should be: the CLI should either fall back gracefully to a working UI when sshd features are unavailable, or show a clear error message instead of silently hanging.

### Environment

```yaml

[q-details]
version = "1.28.0"
hash = "a6ecdf1e1b1391dbc0a620650829a4fc1839425d"
date = "2026-03-20T21:22:23.923553Z (4d ago)"
variant = "minimal"

[system-info]
chip = "AMD EPYC 9354 32-Core
```

Beginne damit, den Hänger in der gemeldeten SSH-Sitzung mit der standardmäßigen UI, --legacy-ui und --tui zu reproduzieren, und überprüfe anschließend q doctor, q restart und /tmp/kiro-debug.log. Als erledigt gilt die Aufgabe, wenn die CLI entweder eine nutzbare UI rendert, sobald die gemeldeten sshd-Funktionen nicht verfügbar sind, oder anstelle eines Hängers nach der Initialisierung einen klaren Fehler anzeigt.

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