fix: suppress double monkey-patch warnings and fork hook assertions

Match gunicorn's patch_all() args exactly (remove subprocess=False),
filter the MonkeyPatchWarning from the unavoidable double-patch, and
wrap gevent's _ForkHooks.after_fork_in_child to catch the spurious
AssertionError that fires when subprocesses fork after double-patching.

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

gunicorn.conf.py

@@ -1,5 +1,12 @@
 """Gunicorn configuration for INTERCEPT."""
 
+import warnings
+warnings.filterwarnings(
+    'ignore',
+    message='Patching more than once',
+    category=DeprecationWarning,
+)
+
 
 def post_fork(server, worker):
     """Apply gevent monkey-patching immediately after fork.
@@ -8,10 +15,30 @@ def post_fork(server, worker):
     some platforms (notably Raspberry Pi / ARM) the worker deadlocks during
     its own init_process() before it gets to patch.  Doing it here — right
     after fork, before any worker initialisation — avoids the race.
+
+    Gunicorn's gevent worker will call patch_all() again in init_process();
+    the duplicate call is harmless (gevent unions the flags) and the
+    MonkeyPatchWarning is suppressed above.
     """
     try:
         from gevent import monkey
-        monkey.patch_all(subprocess=False)
+        monkey.patch_all()
+    except Exception:
+        pass
+
+    # Silence the spurious AssertionError in gevent's fork hooks that fires
+    # when subprocesses fork after a double monkey-patch.
+    try:
+        from gevent.threading import _ForkHooks
+        _orig = _ForkHooks.after_fork_in_child
+
+        def _safe_after_fork(self):
+            try:
+                _orig(self)
+            except AssertionError:
+                pass
+
+        _ForkHooks.after_fork_in_child = _safe_after_fork
     except Exception:
         pass