feat: add versioned research templates and alpha variants

backend/app/research/service.py

@@ -11,7 +11,7 @@ from ..backtests.contracts import Candidate, DraftInput, PreviewInput, Source
 from ..catalog.contracts import EntryOutput, InputPreparation
 from ..catalog.service import Catalog
 from ..models import CatalogEntry
-from .contracts import PLACEHOLDER
+from .expressions import analyze, expand
 
 
 class ResearchBuilder:
@@ -94,9 +94,14 @@ class ResearchBuilder:
                     raise HTTPException(422, "绑定字段不属于该输入快照，不能使用被排除或其他数据集字段")
                 if saved["field_types"].get(binding.field_id) != binding.field_type:
                     raise HTTPException(422, "字段类型声明与输入快照不一致，未知类型不能自动构建")
-            expression = PLACEHOLDER.sub(
-                lambda match: item.bindings[match.group(1)].field_id, item.expression_template
-            )
+            expression = expand(
+                item.expression_template,
+                {name: [binding.field_id] for name, binding in item.bindings.items()},
+                limit=1,
+            )["items"][0]["expression"]
+            validation = analyze(expression, saved["field_types"])
+            if validation["syntax"] or validation["types"]:
+                raise HTTPException(422, "；".join(validation["syntax"] + validation["types"]))
             if len(expression) > 20000:
                 raise HTTPException(422, "绑定后的表达式超过 20000 字符")
             candidates.append(