feat: add overall timeout parameter to remote client (#2550)

## Summary
- Adds an overall `timeout` parameter to `TimeoutConfig` that limits the
total time for the entire request
- Can be set via config or `LANCE_CLIENT_TIMEOUT` environment variable
- Exposed in Python and Node.js bindings
- Includes comprehensive tests

## Test plan
- [x] Unit tests for Rust TimeoutConfig
- [x] Integration tests for Python bindings  
- [x] Integration tests for Node.js bindings
- [x] All existing tests pass

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

python/python/tests/test_remote_db.py

@@ -798,6 +798,21 @@ def test_create_client():
     assert isinstance(db.client_config, ClientConfig)
     assert db.client_config.timeout_config.connect_timeout == timedelta(seconds=42)
 
+    # Test overall timeout parameter
+    db = lancedb.connect(
+        **mandatory_args,
+        client_config=ClientConfig(timeout_config={"timeout": 60}),
+    )
+    assert isinstance(db.client_config, ClientConfig)
+    assert db.client_config.timeout_config.timeout == timedelta(seconds=60)
+
+    db = lancedb.connect(
+        **mandatory_args,
+        client_config={"timeout_config": {"timeout": timedelta(seconds=60)}},
+    )
+    assert isinstance(db.client_config, ClientConfig)
+    assert db.client_config.timeout_config.timeout == timedelta(seconds=60)
+
     db = lancedb.connect(
         **mandatory_args, client_config=ClientConfig(retry_config={"retries": 42})
     )