feat(tests): update performance tests with dynamic minimum throughput for message upsert and update operations

tests/backend/test_performance_hotpaths.py

@@ -11,9 +11,11 @@ Metrics collected:
   - Concurrent writer contention
   - LIKE-search scaling
 
-Latency and single-thread throughput tests use fixed ceilings/floors. Concurrent
-writer tests use the same on non-CI hardware; under CI a lower throughput
-floor applies unless MESHCHATX_PERF_MIN_CONCURRENT_OPS is set.
+Latency and single-thread throughput tests use fixed ceilings/floors. Message
+upsert throughput uses 300 ops/s locally; under CI a lower floor applies unless
+MESHCHATX_PERF_MIN_MESSAGE_UPSERT_OPS is set. Concurrent writer tests use the
+same on non-CI hardware; under CI a lower throughput floor applies unless
+MESHCHATX_PERF_MIN_CONCURRENT_OPS is set.
 """
 
 import os
@@ -35,6 +37,24 @@ from meshchatx.src.backend.message_handler import MessageHandler
 # ---------------------------------------------------------------------------
 
 
+def _min_message_upsert_throughput_ops():
+    """Minimum single-thread upsert/update ops/s for regression tests.
+
+    Local runs use a strict floor (300). CI runners are often noisy; a dip
+    just below 300 is not a regression. Override with
+    MESHCHATX_PERF_MIN_MESSAGE_UPSERT_OPS.
+    """
+    raw = os.environ.get("MESHCHATX_PERF_MIN_MESSAGE_UPSERT_OPS")
+    if raw is not None and raw.strip() != "":
+        try:
+            return max(1, int(raw, 10))
+        except ValueError:
+            pass
+    if os.environ.get("CI"):
+        return 250
+    return 300
+
+
 def _min_concurrent_throughput_ops():
     """Minimum aggregate ops/s for concurrent writer tests.
 
@@ -429,7 +449,12 @@ class TestPerformanceHotPaths(unittest.TestCase):
             durations.append(ms)
 
         stats = latency_report("upsert_message", durations)
-        self.assertGreater(stats["ops"], 300, "Message upsert < 300 ops/s")
+        min_ops = _min_message_upsert_throughput_ops()
+        self.assertGreater(
+            stats["ops"],
+            min_ops,
+            f"Message upsert < {min_ops} ops/s",
+        )
         self.assertLess(stats["p95"], 10, "Message upsert p95 > 10ms")
 
     def test_message_upsert_update_throughput(self):
@@ -450,7 +475,12 @@ class TestPerformanceHotPaths(unittest.TestCase):
             durations.append(ms)
 
         stats = latency_report("update_message", durations)
-        self.assertGreater(stats["ops"], 300, "Message update < 300 ops/s")
+        min_ops = _min_message_upsert_throughput_ops()
+        self.assertGreater(
+            stats["ops"],
+            min_ops,
+            f"Message update < {min_ops} ops/s",
+        )
 
     # ===================================================================
     # CONCURRENT WRITERS — contention stress