Add cloud tasks (#3197)

Adds a TUI for managing, applying, and creating cloud tasks

codex-rs/cloud-tasks/src/new_task.rs

@@ -0,0 +1,35 @@
+use codex_tui::ComposerInput;
+
+pub struct NewTaskPage {
+    pub composer: ComposerInput,
+    pub submitting: bool,
+    pub env_id: Option<String>,
+    pub best_of_n: usize,
+}
+
+impl NewTaskPage {
+    pub fn new(env_id: Option<String>, best_of_n: usize) -> Self {
+        let mut composer = ComposerInput::new();
+        composer.set_hint_items(vec![
+            ("⏎", "send"),
+            ("Shift+⏎", "newline"),
+            ("Ctrl+O", "env"),
+            ("Ctrl+N", "attempts"),
+            ("Ctrl+C", "quit"),
+        ]);
+        Self {
+            composer,
+            submitting: false,
+            env_id,
+            best_of_n,
+        }
+    }
+
+    // Additional helpers can be added as usage evolves.
+}
+
+impl Default for NewTaskPage {
+    fn default() -> Self {
+        Self::new(None, 1)
+    }
+}