Fix run item and batch mode robustness

- run item: rename tum_fime→tum, remove stdout=PIPE (deadlock with
  spawn), support batch mode (-b), SUCCESS on any completed subprocess
  regardless of sub-test result
- batch.py: fix control("loaded") deadlock via daemon thread + Event +
  is_alive() polling; fix premature finish on gd_update messages;
  propagate success flag from finished message; guard control("close")
- process.py: include success flag in send_finished message
- py_process/lua_process: add stdout/stderr=DEVNULL to Popen
- test_run.py: fix finished detection ("id" in m and m["id"] is None)
- testium_win.py: track run_exit_code, SIGABRT handler, clean exit
- __init__.py: sys.exit with batch success flag
- Add run item validation tests and CLAUDE.md documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

doc/manual/sphinx/source/test_items/run_test_item.rst

@@ -8,9 +8,8 @@ This test item executes a new instance of testium.
 
     - run:
         name: Execute TUM
-        tum_fime: example_cycle.tum
+        tum: example_cycle.tum
         python_bin: python3
-        testium_path: /home/francois/projets/testium-new-report/testium.pyw
         log_file: $(home)/reports/test.log
         report_file: $(home)/reports/test.rep
 
@@ -19,7 +18,7 @@ Attributes
 
 run test item has the following specific attributes:
 
-* ``tum_fime``: mandatory the path of the file to execute, it can be relative to current execution folder,
+* ``tum``: mandatory the path of the file to execute, it can be relative to current execution folder,
 * ``param_file`` (optional) the path of the parameter file to use, otherwise default parameter file is used.
 * ``python_bin`` (optional) the path of a specific python to run your scripts,
 * ``testium_path`` (optional) the path of a specific testium to run your scripts,