refactor: make workspace descriptors schema v3 only

backend/src/workspaces/contracts.ts

@@ -1,5 +1,6 @@
 import { validateWorkspaceDescriptor } from "./schema.js";
 import type { DwhTransport, VectorTransport, WorkspaceDescriptor } from "./schema.js";
+import type { DeprecatedV2Descriptor } from "./deprecated-v2-descriptor.js";
 
 export type InstallationRole = "DWH" | "VECTOR" | "VECTOR_WRITER" | "EMBEDDING" | "EVIDENCE";
 export type InstallationSuffix =
@@ -145,25 +146,25 @@ function evidenceVariables(
 export function buildInstallationContract(workspace: WorkspaceDescriptor): InstallationContract {
   const descriptor = validateWorkspaceDescriptor(workspace);
   const namespace = namespaceFor(descriptor);
+  const schemaVersion = Number(descriptor.workspace.schema_version);
+  const legacy = descriptor as unknown as DeprecatedV2Descriptor;
 
   return {
     workspaceId: descriptor.workspace.id,
     namespace,
     variables: [
       ...connectorVariables(namespace, "DWH", descriptor.dwh.supported_transports),
-      ...(descriptor.workspace.schema_version === 2
+      ...(schemaVersion === 2
         ? connectorVariables(
           namespace,
           "VECTOR",
-          "supported_transports" in descriptor.semantic_index.vector_store
-            ? descriptor.semantic_index.vector_store.supported_transports
-            : [],
+          legacy.semantic_index.vector_store.supported_transports,
         )
         : []),
-      ...(descriptor.workspace.schema_version === 2 && descriptor.semantic_index.vector_writer
+      ...(schemaVersion === 2 && legacy.semantic_index.vector_writer
         ? [createVariable(namespace, "VECTOR_WRITER", "API_KEY_FILE")]
         : []),
-      ...(descriptor.workspace.schema_version === 2
+      ...(schemaVersion === 2
         ? EMBEDDING_SUFFIXES.map((suffix) => createVariable(namespace, "EMBEDDING", suffix))
         : []),
       ...evidenceVariables(namespace, descriptor),