feat: add OptimizationTechnique.NONE for non-technique-specific events (meta-pytorch#4025)

Summary:


Add NONE value to OptimizationTechnique enum so general planner events can indicate no specific technique is active.

Differential Revision: D99529682

Author: Ahmed Shuaibi

torchrec/distributed/logging_handlers.py

@@ -10,7 +10,7 @@
 import logging
 from collections import defaultdict
 from enum import Enum
-from typing import Any, Callable, Dict, Generator, Optional, TypeVar
+from typing import Any, Callable, Dict, Generator, List, Optional, TypeVar
 
 from torchrec.distributed.logging_utils import (
     EventLoggingHandlerBase,
@@ -202,4 +202,9 @@ def log_context(
         yield
 
 
+def detect_technique(items: List) -> OptimizationTechnique:  # type: ignore[type-arg]
+    """Detect if EMO is active. No-op OSS stub."""
+    return OptimizationTechnique.NONE
+
+
 _log_handlers: dict[str, logging.Handler] = defaultdict(logging.NullHandler)

torchrec/distributed/logging_utils.py

@@ -37,6 +37,7 @@ class StackLayer(Enum):
 class OptimizationTechnique(Enum):
     """Training optimization techniques."""
 
+    NONE = "none"
     EMO = "emo"
     ITEP = "itep"
     ALBT = "albt"