feat(agent): Refactor agent architecture to enhance content routing and file search capabilities

- Introduced ContentRouterAgent to determine the next step in information gathering (file search, web search, or analysis) based on task relevance and focus mode.
- Added FileSearchAgent to handle searching through attached files, processing file content into searchable documents.
- Updated SynthesizerAgent to utilize a prompt template for generating comprehensive responses based on context and user queries.
- Enhanced TaskManagerAgent to consider file context when creating tasks.
- Improved AnalyzerAgent to assess the sufficiency of context, including file and web documents.
- Implemented utility functions for processing files and ranking documents based on similarity to queries.
- Updated prompts to include new instructions for handling file context and routing decisions.
- Adjusted agent search workflow to integrate new agents and support file handling.

src/lib/agents/agentState.ts

@@ -58,4 +58,12 @@ export const AgentState = Annotation.Root({
     reducer: (x, y) => y ?? x,
     default: () => '',
   }),
+  fileIds: Annotation<string[]>({
+    reducer: (x, y) => y ?? x,
+    default: () => [],
+  }),
+  focusMode: Annotation<string>({
+    reducer: (x, y) => y ?? x,
+    default: () => 'webSearch',
+  }),
 });