fix(ci): handle Windows SQLite WAL lock on test DB cleanup

test_comms.py tearDown: catch PermissionError on os.unlink — Windows
holds WAL handles after SQLite close, causing WinError 32 in CI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: SwiftWing21

tests/test_comms.py

@@ -30,7 +30,10 @@ def tearDown(self):
         except Exception:
             pass
         os.environ.pop("FLEET_TEST_DB", None)
-        os.unlink(self.tmp.name)
+        try:
+            os.unlink(self.tmp.name)
+        except PermissionError:
+            pass  # Windows: SQLite WAL may still hold the file
 
 
 class TestWrapMessage(CommsTestBase):