[core] Stop escalating timeouts (#1853)

## Summary
Escalating out of sandbox is (almost always) not going to fix
long-running commands timing out - therefore we should just pass the
failure back to the model instead of asking the user to re-run a command
that took a long time anyway.

## Testing
- [x] Ran locally with a timeout and confirmed this worked as expected

codex-rs/core/src/exec.rs

@@ -51,6 +51,12 @@ pub struct ExecParams {
     pub env: HashMap<String, String>,
 }
 
+impl ExecParams {
+    pub fn timeout_duration(&self) -> Duration {
+        Duration::from_millis(self.timeout_ms.unwrap_or(DEFAULT_TIMEOUT_MS))
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum SandboxType {
     None,
@@ -83,11 +89,9 @@ pub async fn process_exec_tool_call(
     {
         SandboxType::None => exec(params, sandbox_policy, ctrl_c, stdout_stream.clone()).await,
         SandboxType::MacosSeatbelt => {
+            let timeout = params.timeout_duration();
             let ExecParams {
-                command,
-                cwd,
-                timeout_ms,
-                env,
+                command, cwd, env, ..
             } = params;
             let child = spawn_command_under_seatbelt(
                 command,
@@ -97,14 +101,12 @@ pub async fn process_exec_tool_call(
                 env,
             )
             .await?;
-            consume_truncated_output(child, ctrl_c, timeout_ms, stdout_stream.clone()).await
+            consume_truncated_output(child, ctrl_c, timeout, stdout_stream.clone()).await
         }
         SandboxType::LinuxSeccomp => {
+            let timeout = params.timeout_duration();
             let ExecParams {
-                command,
-                cwd,
-                timeout_ms,
-                env,
+                command, cwd, env, ..
             } = params;
 
             let codex_linux_sandbox_exe = codex_linux_sandbox_exe
@@ -120,7 +122,7 @@ pub async fn process_exec_tool_call(
             )
             .await?;
 
-            consume_truncated_output(child, ctrl_c, timeout_ms, stdout_stream).await
+            consume_truncated_output(child, ctrl_c, timeout, stdout_stream).await
         }
     };
     let duration = start.elapsed();
@@ -255,16 +257,16 @@ pub struct ExecToolCallOutput {
 }
 
 async fn exec(
-    ExecParams {
-        command,
-        cwd,
-        timeout_ms,
-        env,
-    }: ExecParams,
+    params: ExecParams,
     sandbox_policy: &SandboxPolicy,
     ctrl_c: Arc<Notify>,
     stdout_stream: Option<StdoutStream>,
 ) -> Result<RawExecToolCallOutput> {
+    let timeout = params.timeout_duration();
+    let ExecParams {
+        command, cwd, env, ..
+    } = params;
+
     let (program, args) = command.split_first().ok_or_else(|| {
         CodexErr::Io(io::Error::new(
             io::ErrorKind::InvalidInput,
@@ -282,7 +284,7 @@ async fn exec(
         env,
     )
     .await?;
-    consume_truncated_output(child, ctrl_c, timeout_ms, stdout_stream).await
+    consume_truncated_output(child, ctrl_c, timeout, stdout_stream).await
 }
 
 /// Consumes the output of a child process, truncating it so it is suitable for
@@ -290,7 +292,7 @@ async fn exec(
 pub(crate) async fn consume_truncated_output(
     mut child: Child,
     ctrl_c: Arc<Notify>,
-    timeout_ms: Option<u64>,
+    timeout: Duration,
     stdout_stream: Option<StdoutStream>,
 ) -> Result<RawExecToolCallOutput> {
     // Both stdout and stderr were configured with `Stdio::piped()`
@@ -324,7 +326,6 @@ pub(crate) async fn consume_truncated_output(
     ));
 
     let interrupted = ctrl_c.notified();
-    let timeout = Duration::from_millis(timeout_ms.unwrap_or(DEFAULT_TIMEOUT_MS));
     let exit_status = tokio::select! {
         result = tokio::time::timeout(timeout, child.wait()) => {
             match result {