fix: ruff and pyright clean pass

ruff --fix:
- demo.py: remove extraneous f-prefix from plain string literal (F541)
- base_client.py: remove unused AsyncIterator, Iterator imports (F401)
- bedrock/utils.py: remove unused Iterator import (F401); fix import block
  order (I001)
- normalized/chat_models.py: remove unused Iterator import (F401)

ruff format:
- demo.py: expand tuple literal to one-entry-per-line style
- bedrock/utils.py: wrap long _stream_generator signature to fit line-length

pyright (--pythonpath .venv/bin/python):
- bedrock/chat_models.py: UiPathChatBedrockConverse and UiPathChatBedrock mix
  UiPathBaseLLMClient (max_retries: int) with ChatBedrockConverse/ChatBedrock
  (max_retries: int | None); the type narrowing is intentional — our field
  enforces a non-None default of 0 and the httpx client accepts int | None.
  Suppress with # type: ignore[override] on both class definition lines, which
  is the correct pyright mechanism for intentional incompatible base-class field
  merges in multiple-inheritance mixins.

Author: cosminacho

packages/uipath_langchain_client/demo.py

@@ -137,18 +137,29 @@ def calculate(expression: str) -> str:
             expression: A mathematical expression to evaluate (e.g., "2 + 2").
         """
         import ast
+
         try:
             # Restrict to a safe subset: only literals and basic arithmetic operators.
             # This prevents arbitrary code execution via eval().
             tree = ast.parse(expression, mode="eval")
             allowed_node_types = (
-                ast.Expression, ast.BinOp, ast.UnaryOp, ast.Constant,
-                ast.Add, ast.Sub, ast.Mult, ast.Div, ast.FloorDiv,
-                ast.Mod, ast.Pow, ast.USub, ast.UAdd,
+                ast.Expression,
+                ast.BinOp,
+                ast.UnaryOp,
+                ast.Constant,
+                ast.Add,
+                ast.Sub,
+                ast.Mult,
+                ast.Div,
+                ast.FloorDiv,
+                ast.Mod,
+                ast.Pow,
+                ast.USub,
+                ast.UAdd,
             )
             for node in ast.walk(tree):
                 if not isinstance(node, allowed_node_types):
-                    return f"Error: unsupported operation in expression"
+                    return "Error: unsupported operation in expression"
             result = eval(compile(tree, "<string>", "eval"), {"__builtins__": {}})
             return str(result)
         except Exception as e:

packages/uipath_langchain_client/src/uipath_langchain_client/base_client.py

@@ -25,7 +25,7 @@
 
 import logging
 from abc import ABC
-from collections.abc import AsyncGenerator, AsyncIterator, Generator, Iterator, Mapping, Sequence
+from collections.abc import AsyncGenerator, Generator, Mapping, Sequence
 from functools import cached_property
 from typing import Any, Literal
 

packages/uipath_langchain_client/src/uipath_langchain_client/clients/bedrock/chat_models.py

@@ -48,7 +48,7 @@ def _patched_format_data_content_block(block: dict) -> dict:
     ) from e
 
 
-class UiPathChatBedrockConverse(UiPathBaseChatModel, ChatBedrockConverse):
+class UiPathChatBedrockConverse(UiPathBaseChatModel, ChatBedrockConverse):  # type: ignore[override]
     api_config: UiPathAPIConfig = UiPathAPIConfig(
         api_type=ApiType.COMPLETIONS,
         routing_mode=RoutingMode.PASSTHROUGH,
@@ -77,7 +77,7 @@ def setup_uipath_client(self) -> Self:
         return self
 
 
-class UiPathChatBedrock(UiPathBaseChatModel, ChatBedrock):
+class UiPathChatBedrock(UiPathBaseChatModel, ChatBedrock):  # type: ignore[override]
     api_config: UiPathAPIConfig = UiPathAPIConfig(
         api_type=ApiType.COMPLETIONS,
         routing_mode=RoutingMode.PASSTHROUGH,

packages/uipath_langchain_client/src/uipath_langchain_client/clients/bedrock/utils.py

@@ -1,7 +1,7 @@
 import base64
 import json
+from collections.abc import Generator
 from typing import Any
-from collections.abc import Generator, Iterator
 
 from httpx import Client
 
@@ -51,7 +51,9 @@ def __init__(self, httpx_client: Client | None = None, region_name: str = "PLACE
         self.httpx_client = httpx_client
         self.meta = _MockClientMeta(region_name=region_name)
 
-    def _stream_generator(self, request_body: dict[str, Any]) -> Generator[dict[str, Any], None, None]:
+    def _stream_generator(
+        self, request_body: dict[str, Any]
+    ) -> Generator[dict[str, Any], None, None]:
         if self.httpx_client is None:
             raise ValueError("httpx_client is not set")
         with self.httpx_client.stream("POST", "/", json=_serialize_bytes(request_body)) as response:

packages/uipath_langchain_client/src/uipath_langchain_client/clients/normalized/chat_models.py

@@ -24,7 +24,7 @@
 """
 
 import json
-from collections.abc import AsyncGenerator, Callable, Generator, Iterator, Sequence
+from collections.abc import AsyncGenerator, Callable, Generator, Sequence
 from typing import Any
 
 from langchain_core.callbacks import (