feat(plugin): Schema 缓存 — moka LRU Cache 消除 resolve_entity_info 重复查库

- 添加 moka 0.12 依赖到 erp-plugin 和 erp-server
- 重写 state.rs: 新增 EntityInfo (含 generated_fields) 和 moka Cache
- AppState 新增 plugin_entity_cache 字段
- data_service.rs: 旧 resolve_entity_info 保留兼容，新增 resolve_entity_info_cached

crates/erp-server/src/state.rs

@@ -18,6 +18,8 @@ pub struct AppState {
     pub default_tenant_id: uuid::Uuid,
     /// 插件引擎
     pub plugin_engine: erp_plugin::engine::PluginEngine,
+    /// 插件实体缓存
+    pub plugin_entity_cache: moka::sync::Cache<String, erp_plugin::state::EntityInfo>,
 }
 
 /// Allow handlers to extract `DatabaseConnection` directly from `State<AppState>`.
@@ -90,6 +92,7 @@ impl FromRef<AppState> for erp_plugin::state::PluginState {
             db: state.db.clone(),
             event_bus: state.event_bus.clone(),
             engine: state.plugin_engine.clone(),
+            entity_cache: state.plugin_entity_cache.clone(),
         }
     }
 }