Remove REST API, keep GraphQL as sole API

- Add missing GraphQL mutations: retryJob, updateAsset, deleteAsset
- Add UpdateAssetRequest and DeleteResult to schema source of truth
- Move Lambda callback endpoint to main.py (only REST endpoint)
- Remove REST routes, pydantic schemas, and deps
- Remove pydantic target from modelgen.json
- Update architecture diagrams and documentation

api/schema/graphql.py

@@ -104,6 +104,13 @@ class CreateJobInput(graphene.InputObjectType):
     priority = graphene.Int(default_value=0)
 
 
+class UpdateAssetInput(graphene.InputObjectType):
+    """Request body for updating asset metadata."""
+
+    comments = graphene.String()
+    tags = graphene.List(graphene.String)
+
+
 class SystemStatusType(graphene.ObjectType):
     """System status response."""
 
@@ -120,6 +127,12 @@ class ScanResultType(graphene.ObjectType):
     files = graphene.List(graphene.String)
 
 
+class DeleteResultType(graphene.ObjectType):
+    """Result of a delete operation."""
+
+    ok = graphene.Boolean()
+
+
 class WorkerStatusType(graphene.ObjectType):
     """Worker health and capabilities."""