fix(tui): wire ProgramOptions output

Pass the configured output callback into the built-in stdio display terminal so all terminal writes and flushes are redirected as documented. Preserve the controlling TTY for inputTTY mode and cover the callback behavior.

Fixes #6

Author: kingwill101

pkgs/artisanal/lib/src/platform/platform_io.dart

@@ -81,14 +81,20 @@ Future<({int exitCode, String stdout, String stderr})?> runProcess(
   }
 }
 
-Terminal createDefaultTerminal({bool inputTTY = false}) {
+Terminal createDefaultTerminal({
+  bool inputTTY = false,
+  void Function(String)? output,
+}) {
   if (inputTTY) {
     final control = TtyTerminal.tryOpen();
     if (control != null) {
-      return SplitTerminal(control: control, output: StdioTerminal());
+      return SplitTerminal(
+        control: control,
+        output: StdioTerminal(output: output),
+      );
     }
   }
-  return StdioTerminal();
+  return StdioTerminal(output: output);
 }
 
 Stream<List<int>>? ttyOpenRead() {

pkgs/artisanal/lib/src/platform/platform_stub.dart

@@ -30,8 +30,10 @@ Future<({int exitCode, String stdout, String stderr})?> runProcess(
   Map<String, String>? environment,
 }) async => null;
 
-Terminal createDefaultTerminal({bool inputTTY = false}) =>
-    throw UnsupportedError('Default terminal requires dart:io');
+Terminal createDefaultTerminal({
+  bool inputTTY = false,
+  void Function(String)? output,
+}) => throw UnsupportedError('Default terminal requires dart:io');
 
 Stream<List<int>>? ttyOpenRead() => null;
 

pkgs/artisanal/lib/src/terminal/terminal_io_impl.dart

@@ -16,13 +16,18 @@ class StdioTerminal implements Terminal {
   ///
   /// If [stdout] or [stdin] are not provided, uses the process's
   /// standard streams.
-  StdioTerminal({io.Stdout? stdout, io.Stdin? stdin})
+  StdioTerminal({io.Stdout? stdout, io.Stdin? stdin, this.output})
     : _stdout = stdout ?? io.stdout,
       _stdin = stdin ?? io.stdin;
 
   final io.Stdout _stdout;
   final io.Stdin _stdin;
 
+  /// Optional sink for terminal bytes.
+  ///
+  /// When provided, writes are redirected here instead of process stdout.
+  final void Function(String)? output;
+
   // Stdout flush in Dart binds the underlying StreamSink; any concurrent write
   // while a flush is in flight will throw:
   //   StateError: Bad state: StreamSink is bound to a stream
@@ -94,6 +99,11 @@ class StdioTerminal implements Terminal {
   @override
   void write(String text) {
     if (text.isEmpty) return;
+    final sink = output;
+    if (sink != null) {
+      sink(text);
+      return;
+    }
     if (_stdoutFlushInFlight != null) {
       _stdoutPending.write(text);
       _stdoutPendingLen += text.length;
@@ -118,6 +128,7 @@ class StdioTerminal implements Terminal {
 
   @override
   Future<void> flush() {
+    if (output != null) return Future<void>.value();
     final existing = _stdoutFlushInFlight;
     if (existing != null) return existing;
 

pkgs/artisanal/lib/src/terminal/terminal_io_stub.dart

@@ -6,5 +6,5 @@ import 'terminal_base.dart';
 /// Web-safe API stub for the native stdio terminal implementation.
 class StdioTerminal extends StringTerminal {
   /// Creates a stub terminal on platforms without `dart:io`.
-  StdioTerminal({Object? stdout, Object? stdin});
+  StdioTerminal({Object? stdout, Object? stdin, void Function(String)? output});
 }

pkgs/artisanal/lib/src/tui/program.dart

@@ -1602,7 +1602,10 @@ class Program<M extends Model> with HotReloadMixin {
 
   /// Sets up the terminal and renderer.
   Future<void> _setup() async {
-    _terminal ??= platform.createDefaultTerminal(inputTTY: _options.inputTTY);
+    _terminal ??= platform.createDefaultTerminal(
+      inputTTY: _options.inputTTY,
+      output: _options.output,
+    );
 
     // Enable raw mode for character-by-character input
     _terminal!.enableRawMode();

pkgs/artisanal/test/terminal/plumbing_parity_test.dart

@@ -35,6 +35,19 @@ void main() {
       expect(caps.useBackspace, isTrue);
     });
 
+    test(
+      'StdioTerminal redirects writes to the configured output callback',
+      () {
+        final writes = <String>[];
+        final terminal = StdioTerminal(output: writes.add);
+
+        terminal.write('screen bytes');
+        terminal.writeln('line');
+
+        expect(writes, ['screen bytes', 'line${Platform.lineTerminator}']);
+      },
+    );
+
     test('StringTerminal optimizeMovements returns safe defaults', () {
       final terminal = StringTerminal();
       final caps = terminal.optimizeMovements();