chore: 干净 ERP 基座 — 删除 health/ai/wechat 业务代码

删除内容:
- 前端: health/(67文件), ai/(2文件), Copilot, MediaPicker, 相关API/Store/Hook
- 后端: wechat_handler, wechat_service, wechat_user entity, analytics handler, ai_workflow_seed
- 配置: WechatConfig, AppConfig.wechat, AuthState wechat 字段
- 启动: 微信凭据检查块, ensure_ai_workflows() 调用
- 迁移: 新增 m20260613_000170_drop_wechat_users.rs
- 脚本: api_test_health_alert.py, api_test_mp.py, mpsync.sh/ps1
- E2E: health-data page, flows/ 目录

保留: erp-core/auth/workflow/message/config/plugin + 基座前端 + 通用组件

crates/erp-auth/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "erp-auth"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+erp-core.workspace = true
+tokio.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+uuid.workspace = true
+chrono.workspace = true
+axum.workspace = true
+sea-orm.workspace = true
+tracing.workspace = true
+thiserror.workspace = true
+jsonwebtoken.workspace = true
+argon2.workspace = true
+sha2.workspace = true
+validator.workspace = true
+utoipa.workspace = true
+async-trait.workspace = true
+reqwest.workspace = true
+redis.workspace = true
+dashmap.workspace = true