pkg.lib.App: Fix event loop for Python 3.14+

asyncio.get_event_loop() is removed in Python 3.14 when called from
outside an async context. The current code calls it in __init__(),
which crashes on 3.14+.

To fix this, drop the eager loop creation from __init__(). Instead,
lazily create a loop in run() via asyncio.new_event_loop() when no
external loop was provided, and close it in the finally block. This
makes the lifecycle symmetric: run() owns the full create-use-close
cycle and supports re-entrant calls.

Replace __del__() with an explicit close() method, guarding against
double-close via is_closed(). close() always clears __eloop to None
so a closed loop never lingers.

Signed-off-by: Jan Lindemann <jan@janware.com>

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

@@ -84,7 +84,7 @@ class App:  # export
         description: str = '',
         name_filter: str = '^Cmd.*',
         modules: list[str] | None = None,
-        eloop: None = None,
+        eloop: asyncio.AbstractEventLoop | None = None,
     ) -> None:
 
         def add_cmd_to_parser(cmd: AbstractCmd, parsers: Any) -> ArgumentParser:
@@ -171,12 +171,9 @@ class App:  # export
         set_log_flags(self.__default_log_flags)
         set_log_level(self.__default_log_level)
 
+        self.__async_runner: AsyncRunner | None = None
         self.__eloop = eloop
         self.__own_eloop = False
-        if eloop is None:
-            self.__eloop = asyncio.get_event_loop()
-            self.__own_eloop = True
-        self.__async_runner: AsyncRunner | None = None
 
         self.__parser = ArgumentParser(
             formatter_class = ArgumentDefaultsHelpFormatter,
@@ -212,12 +209,12 @@ class App:  # export
             '-h', '--help', action = 'help', help = 'Show this help message and exit'
         )
 
-    def __del__(self) -> None:
+    def close(self) -> None:
         if self.__own_eloop:
             if self.__eloop is not None:
-                self.__eloop.close()
+                if not self.__eloop.is_closed():
+                    self.__eloop.close()
                 self.__eloop = None
-            self.__own_eloop = False
 
     async def __aenter__(self) -> None:
         pass
@@ -333,12 +330,18 @@ class App:  # export
         return self.__parser
 
     def run(self, argv: list[str] | None = None) -> None:
+        if self.__eloop is None:
+            eloop = asyncio.new_event_loop()
+            asyncio.set_event_loop(eloop)
+            self.__eloop = eloop
+            self.__own_eloop = True
         try:
             ret = self.eloop.run_until_complete(self.__run(argv))
         finally:
             if self.__async_runner:
                 self.__async_runner.close()
                 self.__async_runner = None
+            self.close()
         return ret