fix: align research metadata with live WorldQuant responses

backend/app/research/experiments.py

@@ -27,6 +27,17 @@ def scope_of(settings):
     }
 
 
+def seed_settings(snapshot):
+    """Decode executable settings, retaining returned historical dates in the parent snapshot.
+
+    startDate/endDate are result window metadata absent from POST settings. Unknown
+    execution parameters still fail strict validation rather than being discarded.
+    """
+    return SimulationSettings.model_validate(
+        {k: v for k, v in snapshot.items() if k not in ("startDate", "endDate")}
+    )
+
+
 class Experiments:
     def __init__(self, db):
         self.db = db
@@ -315,7 +326,7 @@ class Experiments:
             [parent_snapshot] if parent_snapshot is not None else await self.parents([body.alpha_id], [])
         )
         original = parents[0]
-        base = SimulationSettings.model_validate(original["settings"])
+        base = seed_settings(original["settings"])
         expression = original["expression"]
         snapshots, _ = await self.inputs(body.input_ids)
         groups = defaultdict(list)

backend/app/research/runtime.py

@@ -619,12 +619,15 @@ class ResearchRuntime:
         ):
             raise HTTPException(403, "候选不属于此研究运行的固定输入范围")
         if "backtest" not in run.authorization["methods"] or any(
-            c["settings"]
-            not in (
-                run.authorization.get("allowed_settings", [run.authorization["settings"]])
-                if experiment["evidence"].get("method") == "settings"
-                else [run.authorization["settings"]]
-            )
+            SimulationSettings.model_validate(c["settings"]).model_dump(mode="json")
+            not in [
+                SimulationSettings.model_validate(value).model_dump(mode="json")
+                for value in (
+                    run.authorization.get("allowed_settings", [run.authorization["settings"]])
+                    if experiment["evidence"].get("method") == "settings"
+                    else [run.authorization["settings"]]
+                )
+            ]
             or not c.get("input_ids")
             or any(
                 not any(

backend/app/research/workflows.py

@@ -9,7 +9,7 @@ from ..backtests.contracts import SimulationSettings, fingerprint
 from ..backtests.service import uid
 from ..models import Account, ResearchFlowRun, ResearchStepRun
 from .assets import Assets
-from .experiments import Experiments, scope_of
+from .experiments import Experiments, scope_of, seed_settings
 from .serialization import encode_snapshot as jsonable_encoder
 from .workspace_contracts import WorkflowSpec
 
@@ -195,7 +195,7 @@ class Workflows:
         parents = await experiments.parents(body.parent_alpha_ids, [])
         allowed_settings = [body.settings.model_dump(mode="json")]
         if settings_variant:
-            base = SimulationSettings.model_validate(parents[0]["settings"])
+            base = seed_settings(parents[0]["settings"])
             for snapshot in inputs:
                 scope = snapshot["scope"]
                 target = SimulationSettings.model_validate(