fix: close data integrity and hot-reload review findings

Backfill same-day snapshots for newly added or restored videos, preserve successful fan snapshots on resume, persist incomplete state before forced re-runs, and split collection completion from backup completion so failed backups can retry without API calls. Reject missing data payloads instead of treating them as empty folders, guard against mass-unfav on suspicious empty remote folders, rebuild Bilibili clients when credentials change, recompute primary folder ownership from active relations with per-folder fav_time, preserve original titles for dropped invalid videos, poll config every 60 seconds, and fix favsort verify interval and mixed resource types.

tests/test_cli.py

@@ -51,7 +51,7 @@ def test_init_and_status():
         path = write_config(tmp)
         code, output = run_cli(["init", "--config", str(path)])
         assert code == 0
-        assert '"schema_version": 1' in output
+        assert '"schema_version": 2' in output
 
         db = Database(Path(tmp) / "app.db")
         db.initialize()
@@ -174,6 +174,41 @@ def test_run_once_offline():
         assert selected and all(credentials.mid == 1 for credentials in selected)
 
 
+def test_snapshot_backup_failure_returns_error_and_retries():
+    import reaction_board.services.snapshot as snapshot_module
+
+    with tempfile.TemporaryDirectory() as tmp:
+        path = write_config(tmp, cookie="", csrf="")
+        data = json.loads(path.read_text(encoding="utf-8"))
+        data["folders"] = []
+        data["track_fans"] = []
+        path.write_text(json.dumps(data, ensure_ascii=False), encoding="utf-8")
+
+        original = snapshot_module.backup_daily
+
+        def fail_backup(*args, **kwargs):
+            raise OSError("disk full")
+
+        snapshot_module.backup_daily = fail_backup
+        try:
+            code, output = run_cli(["snapshot", "--config", str(path)])
+        finally:
+            snapshot_module.backup_daily = original
+        assert code == 1
+        marker = output.find("{\n")
+        assert marker >= 0, output
+        payload = json.loads(output[marker:])
+        assert payload["completed"] is True
+        assert "disk full" in payload["backup_error"]
+
+        code, output = run_cli(["snapshot", "--config", str(path)])
+        assert code == 0
+        marker = output.find("{\n")
+        payload = json.loads(output[marker:])
+        assert payload["backup_error"] is None
+        assert Path(payload["backup_path"]).exists()
+
+
 def main_test():
     test_init_and_status()
     test_missing_config()
@@ -182,6 +217,7 @@ def main_test():
     test_auth_check_without_cookie()
     test_auth_check_all_and_auth_dispatch()
     test_run_once_offline()
+    test_snapshot_backup_failure_returns_error_and_retries()
     print("OK: CLI init/sync/snapshot/auth-check/run/status/错误路径测试全部通过")