Structured data 2 (#645)

* Structured data refactor - multi-index tables, remove need for manual mods to the Cassandra tables

* Tech spec updated to track implementation

specs/api/components/schemas/query/ObjectsQueryResponse.yaml

@@ -1,54 +0,0 @@
-type: object
-description: Objects query response (GraphQL format)
-properties:
-  data:
-    description: GraphQL response data (JSON object or null)
-    oneOf:
-      - type: object
-        additionalProperties: {}
-      - type: "null"
-    example:
-      person:
-        name: Alice
-        email: alice@example.com
-        knows:
-          - name: Bob
-          - name: Carol
-  errors:
-    type: array
-    description: GraphQL field-level errors
-    items:
-      type: object
-      properties:
-        message:
-          type: string
-          description: Error message
-          example: Cannot query field 'age' on type 'Person'
-        path:
-          type: array
-          description: Path to error location
-          items:
-            type: string
-          example: ["person", "age"]
-        extensions:
-          type: object
-          description: Additional error metadata
-          additionalProperties:
-            type: string
-  extensions:
-    type: object
-    description: Query metadata (execution time, etc.)
-    additionalProperties:
-      type: string
-    example:
-      execution_time_ms: "42"
-  error:
-    type: object
-    description: System-level error (connection, timeout, etc.)
-    properties:
-      type:
-        type: string
-        example: TIMEOUT_ERROR
-      message:
-        type: string
-        example: Query execution timeout