fix(pkg-py): Pass client method reference instead of calling it

Follow-up to #188. Passing self.client() (calling the method) resulted
in tools being registered twice - once in client() and again in
mod_server - causing "Tool already registered" error.

The fix: pass self.client (method reference) so mod_server can call it
with the update_dashboard and reset_dashboard callbacks.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cpsievert

pkg-py/src/querychat/_querychat.py

@@ -143,7 +143,7 @@ def app_server(input: Inputs, output: Outputs, session: Session):
                 self.id,
                 data_source=self._data_source,
                 greeting=self.greeting,
-                client=self.client(),
+                client=self.client,
                 enable_bookmarking=enable_bookmarking,
             )
 
@@ -809,7 +809,7 @@ def __init__(
             self.id,
             data_source=self._data_source,
             greeting=self.greeting,
-            client=self.client(),
+            client=self.client,
             enable_bookmarking=enable,
         )