feat: lite deep researcher implementation

src/config/configuration.py

@@ -0,0 +1,28 @@
+import os
+from dataclasses import dataclass, fields
+from typing import Any, Optional
+
+from langchain_core.runnables import RunnableConfig
+
+
+@dataclass(kw_only=True)
+class Configuration:
+    """The configurable fields."""
+
+    max_plan_iterations: int = 2  # Maximum number of plan iterations
+    max_step_num: int = 5  # Maximum number of steps in a plan
+
+    @classmethod
+    def from_runnable_config(
+        cls, config: Optional[RunnableConfig] = None
+    ) -> "Configuration":
+        """Create a Configuration instance from a RunnableConfig."""
+        configurable = (
+            config["configurable"] if config and "configurable" in config else {}
+        )
+        values: dict[str, Any] = {
+            f.name: os.environ.get(f.name.upper(), configurable.get(f.name))
+            for f in fields(cls)
+            if f.init
+        }
+        return cls(**{k: v for k, v in values.items() if v})