feat(mycodex): 对齐 resume options，支持 -r/--resume/--continue/--last/--all

- 新增 _translate_codex_extra，将 -r/--resume 映射为 codex resume

- --continue 映射为 codex continue，--last/--all 映射为 resume --last/--all

- 更新 help 文案与 README 用法示例

- 补充 5 个 codex resume option 单元测试，50 tests passed

tests/test_cli.py

@@ -301,6 +301,44 @@ class TestCodexPassthrough:
         assert cmd == ["/usr/bin/codex", "continue"]
 
 
+class TestCodexResumeOptions:
+    """Map myagents-style resume flags to codex resume subcommand."""
+
+    def _invoke(self, args: list[str], tmp_path: Path) -> list[str]:
+        runner = CliRunner()
+        with (
+            patch("myagents.launcher.shutil.which", return_value="/usr/bin/codex"),
+            patch("myagents.launcher.subprocess.run") as mock_run,
+        ):
+            mock_run.return_value = MagicMock(returncode=0)
+            result = runner.invoke(
+                cli, ["codex", "--cwd", str(tmp_path), *args]
+            )
+            assert result.exit_code == 0, result.output
+            mock_run.assert_called_once()
+            return mock_run.call_args[0][0]
+
+    def test_r_flag_maps_to_resume(self, tmp_path: Path) -> None:
+        cmd = self._invoke(["-r", "abc123"], tmp_path)
+        assert cmd == ["/usr/bin/codex", "resume", "abc123"]
+
+    def test_resume_flag_maps_to_resume(self, tmp_path: Path) -> None:
+        cmd = self._invoke(["--resume", "abc123"], tmp_path)
+        assert cmd == ["/usr/bin/codex", "resume", "abc123"]
+
+    def test_continue_flag_maps_to_continue(self, tmp_path: Path) -> None:
+        cmd = self._invoke(["--continue"], tmp_path)
+        assert cmd == ["/usr/bin/codex", "continue"]
+
+    def test_last_flag_maps_to_resume_last(self, tmp_path: Path) -> None:
+        cmd = self._invoke(["--last"], tmp_path)
+        assert cmd == ["/usr/bin/codex", "resume", "--last"]
+
+    def test_all_flag_maps_to_resume_all(self, tmp_path: Path) -> None:
+        cmd = self._invoke(["--all"], tmp_path)
+        assert cmd == ["/usr/bin/codex", "resume", "--all"]
+
+
 class TestCodexListSessions:
     """``myagents codex --list`` reports resumable sessions."""
 

tests/test_entrypoints.py

@@ -102,7 +102,6 @@ class TestMycodexEntrypoint:
             patch("myagents.launcher.subprocess.run") as mock_run,
         ):
             mock_run.return_value = MagicMock(returncode=0)
-            result = runner.invoke(codex_cli, ["--cwd", str(tmp_path), "resume", "abc123"])
+            result = runner.invoke(codex_cli, ["--cwd", str(tmp_path), "-r", "abc123"])
             assert result.exit_code == 0
-            assert "resume" in mock_run.call_args[0][0]
-            assert "abc123" in mock_run.call_args[0][0]
+            assert mock_run.call_args[0][0] == ["/usr/bin/codex", "resume", "abc123"]