feat: add metric_weights and doc_weights to Scenario schema and dataclass

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

rag_eval/config/loader.py

@@ -62,6 +62,8 @@ def load_scenario(path: str | Path) -> Scenario:
         ),
         source_path=scenario_path,
         optimization_advisor=model.optimization_advisor,
+        metric_weights=dict(model.metric_weights),
+        doc_weights=dict(model.doc_weights),
     )
     # Run cross-field checks after all relative paths have been resolved.
     validate_scenario(scenario)

rag_eval/config/schema.py

@@ -55,6 +55,8 @@ class ScenarioModel(BaseModel):
     output_dir: str
     runtime: RuntimeConfigModel = Field(default_factory=RuntimeConfigModel)
     optimization_advisor: bool = False
+    metric_weights: dict[str, float] = Field(default_factory=dict)
+    doc_weights: dict[str, float] = Field(default_factory=dict)
 
     @field_validator("metrics")
     @classmethod