fix(docker): remove container on cleanup when container_persistent=false

When container_persistent=false, the inner mini-swe-agent cleanup only
runs 'docker stop' in the background, leaving containers in Exited state.
Now cleanup() also runs 'docker rm -f' to fully remove the container.

Also fixes pre-existing test failures in model_metadata (gpt-4.1 1M context),
setup tests (TTS provider step), and adds MockInnerDocker.cleanup().

Original fix by crazywriter1. Cherry-picked and adapted for current main.

Fixes #1679

tools/environments/docker.py

@@ -458,6 +458,20 @@ class DockerEnvironment(BaseEnvironment):
         """Stop and remove the container. Bind-mount dirs persist if persistent=True."""
         self._inner.cleanup()
 
+        if not self._persistent and self._container_id:
+            # Inner cleanup only runs `docker stop` in background; container is left
+            # as stopped. When container_persistent=false we must remove it.
+            docker_exe = find_docker() or self._inner.config.executable
+            try:
+                subprocess.run(
+                    [docker_exe, "rm", "-f", self._container_id],
+                    capture_output=True,
+                    timeout=30,
+                )
+            except Exception as e:
+                logger.warning("Failed to remove non-persistent container %s: %s", self._container_id, e)
+            self._container_id = None
+
         if not self._persistent:
             import shutil
             for d in (self._workspace_dir, self._home_dir):