feat(p0): add favorite folder sync and sqlite data foundation

Implement P0 of the reaction dashboard: config loading with hot reload, SQLite migrations with backups, single-writer queue, read-only Bilibili fav client, folder import/diff sync, invalid-resource handling, blacklist seed, scheduler, and JSON redacted logging. Includes offline unit and transport-level contract tests; all existing and new tests pass.

tests/test_moves.py

@@ -0,0 +1,57 @@
+# -*- coding: utf-8 -*-
+"""build_moves / apply_move 的正确性自测（无需 pytest）: python tests/test_moves.py"""
+import os
+import random
+import sys
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+sys.stdout.reconfigure(encoding="utf-8")
+
+from favsort import apply_move, build_moves, lcs_keep  # noqa: E402
+
+
+def run_case(cur, tgt, label):
+    moves = build_moves(cur, tgt)
+    work = list(cur)
+    for m in moves:
+        assert m["pred"] is not None, f"{label}: pred 为空"
+        work = apply_move(work, m)
+    assert work == tgt, f"{label}: 结果不符\n  cur={cur}\n  tgt={tgt}\n  got={work}"
+    lower = len(lcs_keep(cur, tgt))
+    # 不追求严格最优（多轮 LCS 会略多于下界），但不能出现病态膨胀
+    assert len(moves) <= len(cur) + 8, (
+        f"{label}: 步数异常 {len(moves)} (n={len(cur)}, 下界={len(cur) - lower})"
+    )
+    return len(moves)
+
+
+def main():
+    random.seed(20261031)
+    total = 0
+    for n in range(1, 13):
+        ids = [1000 + i for i in range(n)]
+        for _ in range(200):
+            cur = ids[:]
+            tgt = ids[:]
+            random.shuffle(cur)
+            random.shuffle(tgt)
+            run_case(cur, tgt, f"n={n}")
+            total += 1
+
+    # 头部必须换人的用例
+    cases = [
+        ([3, 2, 1], [1, 2, 3]),
+        ([5, 4, 3, 2, 1], [1, 2, 3, 4, 5]),
+        ([2, 3, 1], [1, 2, 3]),
+        ([4, 1, 2, 3], [1, 2, 3, 4]),
+    ]
+    for cur, tgt in cases:
+        run_case(cur, tgt, f"head {cur}->{tgt}")
+
+    # 已排序不应产生移动
+    assert build_moves([1, 2, 3], [1, 2, 3]) == []
+    print(f"OK: {total} 个随机用例 + {len(cases)} 个头部用例全部通过")
+
+
+if __name__ == "__main__":
+    main()