lib.App: Warn on invalid exit status

__run() only accepts a return value from _run() as the process exit
status if it is an int between 0 and 255, and silently drops any other
value. A command that returns, for instance, 300 therefore exits with
status 0, which presents a failure as a success to the caller without
any trace of the mistake.

Log an error when the returned exit status is out of range so that the
programming error is visible, while still exiting with 0 instead of
passing an invalid status to the shell.

Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v0.84.2
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/App.py

@@ -300,9 +300,17 @@ class App:  # export
             pr.enable()
 
         try:
-            ret = await self._run(self.__args)
+            result = await self._run(self.__args)
-            if isinstance(ret, int) and ret >= 0 and ret <= 0xFF:
+            if isinstance(result, int):
-                exit_status = ret
+                if 0 <= result <= 0xFF:
+                    exit_status = result
+                else:
+                    log(
+                        WARNING,
+                        f'Command returned invalid exit status {result}, '
+                        'using 1 instead',
+                    )
+                    exit_status = 1
         except Exception as e:
             log_m(ERR, f'Failed: {repr(e) if self.__back_trace else str(e)}')
             exit_status = 1