feat(server): erp-ai 模块集成 — Config/State/路由注册

- 新增 AiConfig 到 AppConfig
- 新增 FromRef<AppState> for AiState
- 注册 AiModule 到 ModuleRegistry
- 合并 AI protected routes
- 修复 sync_module_permissions 只同步 health.% 的 bug

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/erp-server/src/config.rs

@@ -11,6 +11,7 @@ pub struct AppConfig {
     pub cors: CorsConfig,
     pub wechat: WechatConfig,
     pub health: HealthConfig,
+    pub ai: AiConfig,
 }
 
 #[derive(Debug, Clone, Deserialize)]
@@ -69,6 +70,18 @@ pub struct HealthConfig {
     pub hmac_key: String,
 }
 
+#[derive(Debug, Clone, Deserialize)]
+pub struct AiConfig {
+    pub default_provider: String,
+    pub api_key: String,
+    pub base_url: Option<String>,
+    pub model: String,
+    pub max_tokens: u32,
+    pub temperature: f32,
+    pub cache_ttl_seconds: u64,
+    pub rate_limit_patient_daily: u32,
+}
+
 impl AppConfig {
     pub fn load() -> anyhow::Result<Self> {
         let config = config::Config::builder()