feat(chat): enhance chat functionality with web search and article integration

- Updated ChatMessage and ChatWindow components to support inline web search results and articles.
- Integrated new web search and RSS plugins into the chat system for real-time information retrieval.
- Enhanced useContentPanel to manage web search results alongside existing media types.
- Added ArticleOverlay component for displaying selected articles from search results.
- Improved UI elements and styles for better user interaction with web search features.

Made-with: Cursor

packages/core/src/types/message.ts

@@ -1,5 +1,13 @@
 import type { ContentBlock } from './content'
 
+export interface WebSearchResult {
+  title: string
+  url: string
+  content?: string
+  /** Image/thumbnail URL from search engine (e.g. SearXNG img_src) */
+  imgSrc?: string
+}
+
 export interface Message {
   id: string
   role: 'user' | 'assistant' | 'system'
@@ -11,6 +19,8 @@ export interface Message {
   replyTo?: string
   reactions?: Reaction[]
   status?: 'sending' | 'sent' | 'delivered' | 'read' | 'error'
+  /** Web search results (articles, links) attached when query used web search */
+  webResults?: WebSearchResult[]
 }
 
 export interface Reaction {