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/index.ts

@@ -3,3 +3,5 @@ export { WebSearchAgent } from './webSearchAgent';
 export { AnalyzerAgent } from './analyzerAgent';
 export { SynthesizerAgent } from './synthesizerAgent';
 export { TaskManagerAgent } from './taskManagerAgent';
+export { FileSearchAgent } from './fileSearchAgent';
+export { ContentRouterAgent } from './contentRouterAgent';