fix(hush): clear no-TTY error for the interactive TUI

CHANGELOG.md

@@ -47,6 +47,7 @@
 
 ### Fixed
 
+- hush: TUI now reports a clear "no TTY" error with subcommand guidance instead of crossterm's cryptic "Device not configured" failure (#57)
 - remediate merged-#35 CodeRabbit findings (#36) [#35]
 - post-merge remediation for #33 (validator hardening, packaging hygiene, ask-codex metadata) (#34) [#33]
 - complete issue #10 port hardening (#33) [#10]

bws-tui/src/tui/terminal.rs

@@ -1,11 +1,11 @@
 use super::{events, App};
-use anyhow::{anyhow, Context, Result};
+use anyhow::{anyhow, bail, Context, Result};
 use crossterm::{
     execute,
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
 };
 use ratatui::{backend::CrosstermBackend, Terminal};
-use std::io::{self, Write};
+use std::io::{self, IsTerminal, Write};
 
 #[derive(Default)]
 struct TerminalGuard {
@@ -50,6 +50,13 @@ impl Drop for TerminalGuard {
 }
 
 pub(super) fn run(app: &mut App) -> Result<()> {
+    if !is_interactive(io::stdin().is_terminal(), io::stdout().is_terminal()) {
+        bail!(
+            "hush's interactive TUI needs a terminal session (no TTY found). \
+             Run `hush` from an interactive terminal, or use the script-friendly \
+             subcommands: `hush list`, `hush get --key <KEY>`, `hush exec --key <KEY> -- <cmd>`"
+        );
+    }
     let mut guard = TerminalGuard::default();
     guard.enable_raw()?;
     let mut output = io::stdout();
@@ -60,6 +67,12 @@ pub(super) fn run(app: &mut App) -> Result<()> {
     finish_terminal(event, raw, screen)
 }
 
+/// The TUI needs either side attached to a terminal; crossterm opens /dev/tty
+/// directly for input when stdin is piped, so stdout alone is enough.
+pub(super) fn is_interactive(stdin_tty: bool, stdout_tty: bool) -> bool {
+    stdin_tty || stdout_tty
+}
+
 pub(super) fn finish_terminal(
     event: Result<()>,
     raw: Result<()>,

bws-tui/src/tui/tests.rs

@@ -1,4 +1,5 @@
 use super::*;
+use crate::tui::terminal::is_interactive;
 use anyhow::anyhow;
 
 #[test]
@@ -52,6 +53,14 @@ fn edit_fields_cycle_without_invalid_numeric_states() {
     assert_eq!(EditField::Key.previous(), EditField::Note);
 }
 
+#[test]
+fn tui_gate_accepts_a_tty_on_either_side() {
+    assert!(is_interactive(true, false));
+    assert!(is_interactive(false, true));
+    assert!(is_interactive(true, true));
+    assert!(!is_interactive(false, false));
+}
+
 #[test]
 fn terminal_cleanup_reports_every_failure() {
     let error = terminal::finish_terminal(