fix: gracefully handle unknown event types in Python SDK

The v3 server broadcasts new event types like permission.completed that
the generated session_events.py can't deserialize yet. Wrap
session_event_from_dict in try/except so unknown events are silently
skipped instead of crashing the notification handler. This affects both
the stdio and TCP connection handlers.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: patniko

python/copilot/client.py

@@ -1348,11 +1348,14 @@ def handle_notification(method: str, params: dict):
             if method == "session.event":
                 session_id = params["sessionId"]
                 event_dict = params["event"]
-                # Convert dict to SessionEvent object
-                event = session_event_from_dict(event_dict)
+                # Convert dict to SessionEvent object (skip unknown event types)
+                try:
+                    event = session_event_from_dict(event_dict)
+                except Exception:
+                    event = None
                 with self._sessions_lock:
                     session = self._sessions.get(session_id)
-                if session:
+                if session and event:
                     session._dispatch_event(event)
 
                 # v3 protocol: intercept tool/permission broadcast events
@@ -1442,10 +1445,13 @@ def handle_notification(method: str, params: dict):
             if method == "session.event":
                 session_id = params["sessionId"]
                 event_dict = params["event"]
-                # Convert dict to SessionEvent object
-                event = session_event_from_dict(event_dict)
+                # Convert dict to SessionEvent object (skip unknown event types)
+                try:
+                    event = session_event_from_dict(event_dict)
+                except Exception:
+                    event = None
                 session = self._sessions.get(session_id)
-                if session:
+                if session and event:
                     session._dispatch_event(event)
 
                 # v3 protocol: intercept tool/permission broadcast events