refactor: Address code review feedback for field modifier ordering

Address valid GitHub Copilot feedback:

1. Replace magic number index access in FT.INFO parsing
   - Changed info[7] to proper key-based lookup for 'attributes'
   - More resilient to Redis response format changes
   - Added helpful error message if key not found

2. Enhance time complexity documentation
   - Added detailed breakdown of O(n + m) complexity
   - Clarified set creation and lookup costs

Rejected feedback about testing implementation details - unit tests
appropriately test the _normalize_field_modifiers helper function
directly, while integration tests verify end-to-end behavior.

Author: nkanu17

redisvl/schema/fields.py

@@ -114,7 +114,9 @@ def _normalize_field_modifiers(
         canonical_order: List of modifiers in desired canonical order
         want_unf: Whether UNF should be added after SORTABLE (default: False)
 
-    Time Complexity: O(n + m) where n = len(field.args_suffix), m = len(canonical_order)
+    Time Complexity: O(n + m), where n = len(field.args_suffix), m = len(canonical_order).
+        - O(n) to create the set from field.args_suffix
+        - O(m) to iterate over canonical_order and perform set lookups (O(1) average case per lookup)
     Space Complexity: O(n)
 
     Example:

tests/integration/test_field_modifier_ordering_integration.py

@@ -297,7 +297,13 @@ def test_mixed_field_types_with_modifiers(self, client, redis_url, worker_id):
         assert info is not None
 
         # Verify all fields were created
-        attrs_list = info[7]
+        # Find the 'attributes' key in the FT.INFO response (flat list format)
+        attrs_list = None
+        for i in range(0, len(info) - 1, 2):
+            if info[i] == b"attributes" or info[i] == "attributes":
+                attrs_list = info[i + 1]
+                break
+        assert attrs_list is not None, "'attributes' key not found in FT.INFO response"
         assert len(attrs_list) == 4
 
         # Cleanup