feat: 添加密码管理功能，包括 API、数据库支持和前端界面

apps/server/migrations/0004_credentials.sql

@@ -0,0 +1,17 @@
+create table if not exists credentials (
+  id uuid primary key default gen_random_uuid(),
+  user_id uuid not null references users(id) on delete cascade,
+  site_origin text not null,
+  username text not null,
+  password_enc text not null,
+  password_iv text not null,
+  password_tag text not null,
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now()
+);
+
+create unique index if not exists idx_credentials_user_origin_username
+  on credentials (user_id, site_origin, username);
+
+create index if not exists idx_credentials_user_origin
+  on credentials (user_id, site_origin);