[mmu probing] pr06.probe: Add base framework and all probing implementations

tests/saitests/probe/__init__.py

@@ -0,0 +1,48 @@
+"""
+SONiC Buffer Threshold Probing Module
+
+This module contains probing test cases for MMU threshold detection,
+using the Template Method Pattern for clean architecture.
+
+Architecture:
+- ProbingBase: Base class with template method runTest()
+  - setUp(): PTF init + common parse_param
+  - runTest(): Template - calls setup_traffic() + probe()
+  - tearDown(): PTF cleanup
+
+Probing Test Cases (1 src -> N dst pattern):
+- PfcXoffProbing: PFC Xoff threshold probing
+- IngressDropProbing: Ingress Drop threshold probing
+
+Probing Test Cases (N src -> 1 dst pattern):
+- HeadroomPoolProbing: Headroom Pool Size probing (multi-PG iteration)
+
+Supporting Components:
+- Algorithm: UpperBound, LowerBound, ThresholdRange, ThresholdPoint
+- Executor: Lazy loaded via ExecutorRegistry
+- Observer: ProbingObserver with ObserverConfig
+- BufferOccupancyController: TX state and buffer management
+- ExecutorRegistry: Factory for environment-specific executors (physical/mock)
+
+Usage in test_qos_sai.py:
+    # PFC Xoff probing
+    self.runPtfTest(ptfhost, testCase="pfc_xoff_probing.PfcXoffProbing",
+                    testParams=testParams, test_subdir='probe')
+
+    # Ingress Drop probing
+    self.runPtfTest(ptfhost, testCase="ingress_drop_probing.IngressDropProbing",
+                    testParams=testParams, test_subdir='probe')
+
+    # Headroom Pool probing
+    self.runPtfTest(ptfhost, testCase="headroom_pool_probing.HeadroomPoolProbing",
+                    testParams=testParams, test_subdir='probe')
+
+Extensibility:
+    # For UT/mock, register mock executors:
+    from executor_registry import ExecutorRegistry
+    ExecutorRegistry.register('pfc_xoff', 'mock', 'MockPfcXoffExecutor', 'mock.MockPfcXoffExecutor')
+"""
+
+__version__ = "0.1.0"
+
+# No module-level imports - PTF loads test classes directly