feat: implement immutable form definitions

src/govoplan_forms/backend/schemas.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from typing import Any
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class FormDefinitionWriteRequest(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+
+    definition: dict[str, Any]
+    expected_revision: str | None = Field(default=None, min_length=1, max_length=255)
+
+
+class FormDefinitionListResponse(BaseModel):
+    definitions: list[dict[str, Any]]
+    total: int
+
+
+class FormDefinitionHistoryResponse(BaseModel):
+    revisions: list[dict[str, Any]]
+
+
+__all__ = [
+    "FormDefinitionHistoryResponse",
+    "FormDefinitionListResponse",
+    "FormDefinitionWriteRequest",
+]