mod: use unbuffered streaming writer for TUIs

examples/demo.zig

@@ -31,8 +31,9 @@ pub fn main(init: std.process.Init) !void {
 
     var app: App = .init(gpa, io, .{});
     var stdout = std.Io.File.stdout();
-    var stdout_buffer: [4096]u8 = undefined;
-    var writer = stdout.writerStreaming(io, &stdout_buffer);
+    // var stdout_buffer: [4096]u8 = undefined;
+    // var writer = stdout.writerStreaming(io, &stdout_buffer);
+    var writer = stdout.writerStreaming(io, &.{});
     const w = &writer.interface;
     defer w.flush() catch |err| log.err("Could not flush: {any}", .{err});
 
@@ -186,6 +187,7 @@ pub fn main(init: std.process.Init) !void {
         container.reposition(&app.model, .{});
         try renderer.render(@TypeOf(container), &container, App.Model, &app.model);
         try renderer.flush(w);
+        try w.flush();
     }
 }