feat(auth): 增加登录验证和五天会话

migrations/002_site_auth.sql

@@ -0,0 +1,10 @@
+-- 单管理员账号；密码仅保存 Werkzeug 生成的单向哈希。
+CREATE TABLE IF NOT EXISTS weread_auth (
+    id TINYINT UNSIGNED NOT NULL,
+    username VARCHAR(64) NOT NULL,
+    password_hash VARCHAR(255) NOT NULL,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    PRIMARY KEY (id),
+    UNIQUE KEY uq_weread_auth_username (username)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='阅间访问账号';