Unify runtime state in SQLite and add rollout observability

tests/test_probability_snapshot_archive.py

@@ -1,9 +1,15 @@
 import json
 from pathlib import Path
+import pytest
 
 from src.analysis.probability_snapshot_archive import append_probability_snapshot
 
 
+@pytest.fixture(autouse=True)
+def _force_file_mode(monkeypatch):
+    monkeypatch.setenv("POLYWEATHER_STATE_STORAGE_MODE", "file")
+
+
 def test_append_probability_snapshot_writes_jsonl(tmp_path: Path):
     archive_path = tmp_path / "probability_training_snapshots.jsonl"