feat: add schema drift handling and rebuild

backend/tests/test_schema_drift.py

@@ -0,0 +1,37 @@
+import os
+import tempfile
+import sqlite3
+
+import backend.db as db_mod
+
+
+
+def _setup_temp_db_with_m2_schema(tmp_dir: str) -> str:
+    db_path = os.path.join(tmp_dir, "test.db")
+    conn = sqlite3.connect(db_path)
+    # create old settings table
+    conn.execute("CREATE TABLE settings (key TEXT PRIMARY KEY, value TEXT, value_enc TEXT)")
+    conn.commit()
+    conn.close()
+    return db_path
+
+
+def test_drift_detection_and_rebuild(monkeypatch):
+    with tempfile.TemporaryDirectory() as tmp:
+        db_path = _setup_temp_db_with_m2_schema(tmp)
+        monkeypatch.setenv("SLAB_DB_PATH", db_path)
+        # init_db should rebuild
+        conn = db_mod.init_db()
+        # check schema_version exists
+        cur = conn.execute("SELECT version FROM schema_version").fetchone()
+        assert cur is not None
+        assert cur[0] == 1
+        # check settings has columns value and value_enc
+        info = conn.execute("PRAGMA table_info(settings)").fetchall()
+        cols = {row[1] for row in info}
+        assert "value" in cols
+        assert "value_enc" in cols
+        # also ensure old settings table dropped and recreated
+        # no other data
+        rows = conn.execute("SELECT key FROM settings").fetchall()
+        assert rows == []