fix(desktop): DeerFlow UI — ChatArea refactor + ai-elements + dead CSS cleanup

ChatArea retry button uses setInput instead of direct sendToGateway,
fix bootstrap spinner stuck for non-logged-in users,
remove dead CSS (aurora-title/sidebar-open/quick-action-chips),
add ai components (ReasoningBlock/StreamingText/ChatMode/ModelSelector/TaskProgress),
add ClassroomPlayer + ResizableChatLayout + artifact panel

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/zclaw-saas/src/cache.rs

@@ -167,6 +167,22 @@ impl AppCache {
         self.relay_queue_counts.retain(|k, _| db_keys.contains(k));
     }
 
+    // ============ 快捷查找（Phase 2: 减少关键路径 DB 查询） ============
+
+    /// 按 model_id 查找已启用的模型。O(1) DashMap 查找。
+    pub fn get_model(&self, model_id: &str) -> Option<CachedModel> {
+        self.models.get(model_id)
+            .filter(|m| m.enabled)
+            .map(|r| r.value().clone())
+    }
+
+    /// 按 provider id 查找已启用的 Provider。O(1) DashMap 查找。
+    pub fn get_provider(&self, provider_id: &str) -> Option<CachedProvider> {
+        self.providers.get(provider_id)
+            .filter(|p| p.enabled)
+            .map(|r| r.value().clone())
+    }
+
     // ============ 缓存失效 ============
 
     /// 清除 model 缓存中的指定条目（Admin CRUD 后调用）