fix(skills): lock usage telemetry updates

tests/tools/test_skill_usage.py

@@ -1,12 +1,21 @@
 """Tests for tools/skill_usage.py — sidecar telemetry + provenance filtering."""
 
 import json
+import multiprocessing as mp
 import os
 from pathlib import Path
 
 import pytest
 
 
+def _bump_view_many(hermes_home: str, skill_name: str, iterations: int) -> None:
+    os.environ["HERMES_HOME"] = hermes_home
+    from tools.skill_usage import bump_view
+
+    for _ in range(iterations):
+        bump_view(skill_name)
+
+
 @pytest.fixture
 def skills_home(tmp_path, monkeypatch):
     """Isolated HERMES_HOME with a clean skills/ dir for each test."""
@@ -139,6 +148,30 @@ def test_bumps_do_not_corrupt_other_skills(skills_home):
     assert get_record("skill-b")["use_count"] == 1
 
 
+def test_concurrent_bump_view_preserves_all_updates(skills_home):
+    from tools.skill_usage import get_record
+
+    process_count = 6
+    iterations = 25
+    ctx = mp.get_context("spawn")
+    processes = [
+        ctx.Process(
+            target=_bump_view_many,
+            args=(str(skills_home), "shared-skill", iterations),
+        )
+        for _ in range(process_count)
+    ]
+
+    for process in processes:
+        process.start()
+    for process in processes:
+        process.join(timeout=20)
+
+    for process in processes:
+        assert process.exitcode == 0
+    assert get_record("shared-skill")["view_count"] == process_count * iterations
+
+
 # ---------------------------------------------------------------------------
 # State transitions
 # ---------------------------------------------------------------------------