Refactor workflow-logic-function-interaction (#17699)

# Refactor workflow–logic function interaction

## Why

Workflow code steps and standalone logic functions shared the same build
layer and DB layer, which blurred two use cases: code steps belong to a
workflow version; standalone functions are deployable units. That made
workflow code steps harder to own and evolve.

## Goal

Treat code steps as **workflow-owned**: build and run them in workflow
context, and expose workflow-scoped APIs so the editor can load, test,
and save code step source without going through the generic
logic-function layer.

packages/twenty-front/src/modules/logic-functions/hooks/useGetLogicFunctionSourceCode.ts

@@ -0,0 +1,34 @@
+import { useApolloCoreClient } from '@/object-metadata/hooks/useApolloCoreClient';
+import { GET_LOGIC_FUNCTION_SOURCE_CODE } from '@/logic-functions/graphql/queries/getLogicFunctionSourceCode';
+import { useQuery } from '@apollo/client';
+import { type Sources } from 'twenty-shared/types';
+import {
+  type GetLogicFunctionSourceCodeQuery,
+  type GetLogicFunctionSourceCodeQueryVariables,
+} from '~/generated-metadata/graphql';
+
+export const useGetLogicFunctionSourceCode = ({
+  logicFunctionId,
+}: {
+  logicFunctionId: string;
+}): { code: Sources | null; loading: boolean } => {
+  const apolloMetadataClient = useApolloCoreClient();
+  const { data, loading } = useQuery<
+    GetLogicFunctionSourceCodeQuery,
+    GetLogicFunctionSourceCodeQueryVariables
+  >(GET_LOGIC_FUNCTION_SOURCE_CODE, {
+    client: apolloMetadataClient ?? undefined,
+    variables: {
+      input: { id: logicFunctionId },
+    },
+    skip: !logicFunctionId,
+  });
+
+  const raw = data?.getLogicFunctionSourceCode;
+  const code =
+    raw != null && typeof raw === 'object' && !Array.isArray(raw)
+      ? (raw as Sources)
+      : null;
+
+  return { code, loading };
+};