fix: guard STDIN reference for non-CLI invocations of AbstractCommand

Page-cache tests in CodeIgniterTest exercise command() from an HTTP
context where STDIN is not defined globally. Bare `STDIN` inside the
CodeIgniter\CLI namespace fails to resolve in that mode. Guard with
defined() and use \STDIN explicitly; a non-CLI caller cannot prompt,
so the correct semantic is non-interactive.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

Author: paulbalandan

system/CLI/AbstractCommand.php

@@ -357,13 +357,20 @@ public function hasNegation(string $name): bool
      *   1. An explicit `setInteractive()` call wins.
      *   2. Otherwise, the command is interactive when STDIN is a TTY.
      *
+     * Non-CLI contexts (e.g., a controller invoking `command()`) don't expose
+     * `STDIN` at all — those always resolve as non-interactive.
+     *
      * Note: the `--no-interaction` / `-N` flag is folded into the explicit state
      * by `run()` before interactive hooks fire, so callers do not need to
      * inspect the options array themselves.
      */
     public function isInteractive(): bool
     {
-        return $this->interactive ?? CLI::streamSupports('stream_isatty', STDIN);
+        if ($this->interactive !== null) {
+            return $this->interactive;
+        }
+
+        return defined('STDIN') && CLI::streamSupports('stream_isatty', \STDIN);
     }
 
     /**