feat(saas): Phase 1 — 基础框架与账号管理模块

- 新增 zclaw-saas crate 作为 workspace 成员
- 配置系统 (TOML + 环境变量覆盖)
- 错误类型体系 (SaasError 16 变体, IntoResponse)
- SQLite 数据库 (12 表 schema, 内存/文件双模式, 3 系统角色种子数据)
- JWT 认证 (签发/验证/刷新)
- Argon2id 密码哈希
- 认证中间件 (公开/受保护路由分层)
- 账号管理 CRUD + API Token 管理 + 操作日志
- 7 单元测试 + 5 集成测试全部通过

Cargo.toml

@@ -15,6 +15,8 @@ members = [
     "crates/zclaw-growth",
     # Desktop Application
     "desktop/src-tauri",
+    # SaaS Backend
+    "crates/zclaw-saas",
 ]
 
 [workspace.package]
@@ -95,6 +97,16 @@ shlex = "1"
 # Testing
 tempfile = "3"
 
+# SaaS dependencies
+axum = { version = "0.7", features = ["macros"] }
+axum-extra = { version = "0.9", features = ["typed-header"] }
+tower = { version = "0.4", features = ["util"] }
+tower-http = { version = "0.5", features = ["cors", "trace", "limit"] }
+jsonwebtoken = "9"
+argon2 = "0.5"
+totp-rs = "5"
+hex = "0.4"
+
 # Internal crates
 zclaw-types = { path = "crates/zclaw-types" }
 zclaw-memory = { path = "crates/zclaw-memory" }
@@ -106,6 +118,7 @@ zclaw-channels = { path = "crates/zclaw-channels" }
 zclaw-protocols = { path = "crates/zclaw-protocols" }
 zclaw-pipeline = { path = "crates/zclaw-pipeline" }
 zclaw-growth = { path = "crates/zclaw-growth" }
+zclaw-saas = { path = "crates/zclaw-saas" }
 
 [profile.release]
 lto = true