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_migrations.py

@@ -0,0 +1,150 @@
+# -*- coding: utf-8 -*-
+"""SQLite 迁移测试（不联网）: uv run python tests/test_migrations.py"""
+
+import os
+import sqlite3
+import sys
+import tempfile
+from pathlib import Path
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+sys.stdout.reconfigure(encoding="utf-8")
+
+from reaction_board.migrations import (  # noqa: E402
+    MIGRATIONS,
+    Migration,
+    MigrationError,
+    current_version,
+    prune_backups,
+    run_migrations,
+)
+
+EXPECTED_TABLES = {
+    "video", "snapshot", "folder", "folder_resource", "up_blacklist",
+    "up_stat", "candidate", "seen_aid", "notify", "fav_action", "kv",
+}
+
+
+def table_names(conn):
+    rows = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type = 'table' AND name NOT LIKE 'sqlite_%'"
+    ).fetchall()
+    return {row[0] for row in rows}
+
+
+def test_fresh_and_idempotent():
+    with tempfile.TemporaryDirectory() as tmp:
+        conn = sqlite3.connect(Path(tmp) / "app.db")
+        try:
+            applied = run_migrations(conn)
+            assert applied == [1]
+            assert current_version(conn) == 1
+            assert EXPECTED_TABLES <= table_names(conn)
+            assert "schema_version" in table_names(conn)
+            # 再跑一次不应重复应用
+            assert run_migrations(conn) == []
+            row = conn.execute("SELECT COUNT(*) FROM schema_version").fetchone()
+            assert row[0] == 1
+        finally:
+            conn.close()
+
+
+def test_backup_before_upgrade():
+    with tempfile.TemporaryDirectory() as tmp:
+        db_path = Path(tmp) / "app.db"
+        backup_dir = Path(tmp) / "backup"
+        conn = sqlite3.connect(db_path)
+        try:
+            run_migrations(conn, backup_dir=backup_dir)
+            conn.execute("INSERT INTO kv(k, v) VALUES ('hello', 'world')")
+            conn.commit()
+
+            v2 = Migration(2, "add probe", ("CREATE TABLE probe (id INTEGER PRIMARY KEY)",))
+            applied = run_migrations(
+                conn,
+                backup_dir=backup_dir,
+                now=1_800_000_000,
+                migrations=MIGRATIONS + (v2,),
+            )
+            assert applied == [2]
+            backups = list(backup_dir.glob("app-pre-v1-*.db"))
+            assert len(backups) == 1
+            check = sqlite3.connect(backups[0])
+            try:
+                assert check.execute("SELECT v FROM kv WHERE k='hello'").fetchone()[0] == "world"
+                assert "probe" not in table_names(check)
+            finally:
+                check.close()
+        finally:
+            conn.close()
+
+
+def test_failed_migration_rolls_back():
+    with tempfile.TemporaryDirectory() as tmp:
+        conn = sqlite3.connect(Path(tmp) / "app.db")
+        bad = Migration(
+            1,
+            "broken",
+            (
+                "CREATE TABLE should_not_exist (id INTEGER PRIMARY KEY)",
+                "CREATE TABLE broken (",
+            ),
+        )
+        try:
+            try:
+                run_migrations(conn, migrations=(bad,))
+            except MigrationError as exc:
+                assert "已回滚" in str(exc)
+            else:
+                raise AssertionError("坏迁移应抛错")
+            assert "should_not_exist" not in table_names(conn)
+            assert current_version(conn) == 0
+        finally:
+            conn.close()
+
+
+def test_prune_backups():
+    with tempfile.TemporaryDirectory() as tmp:
+        backup_dir = Path(tmp)
+        old = backup_dir / "app-pre-v1-old.db"
+        fresh = backup_dir / "app-pre-v1-fresh.db"
+        other = backup_dir / "keep.txt"
+        for path in (old, fresh, other):
+            path.write_bytes(b"x")
+        now = 1_800_000_000
+        old_time = now - 20 * 86400
+        os.utime(old, (old_time, old_time))
+        os.utime(fresh, (now, now))
+        removed = prune_backups(backup_dir, keep_days=14, now=now)
+        assert removed == [old]
+        assert fresh.exists() and other.exists()
+
+
+def test_validate_migration_order():
+    with tempfile.TemporaryDirectory() as tmp:
+        conn = sqlite3.connect(Path(tmp) / "app.db")
+        try:
+            try:
+                run_migrations(conn, migrations=(
+                    Migration(2, "x", ()),
+                    Migration(1, "y", ()),
+                ))
+            except ValueError as exc:
+                assert "升序" in str(exc)
+            else:
+                raise AssertionError("乱序迁移应失败")
+        finally:
+            conn.close()
+
+
+def main():
+    test_fresh_and_idempotent()
+    test_backup_before_upgrade()
+    test_failed_migration_rolls_back()
+    test_prune_backups()
+    test_validate_migration_order()
+    print("OK: SQLite 迁移、备份与回滚测试全部通过")
+
+
+if __name__ == "__main__":
+    main()