Refactor agent function names and streamline imports

Unified the naming convention for agent functions across modules to `agent` for consistency. Adjusted relevant imports and cleaned up unused imports in `webhooks.rs` to improve readability and maintainability.

src/agents/news.rs

@@ -1,6 +1,6 @@
 use crate::utils::utils::run_agent;
 use tokio::process::Child;
 
-pub async fn news_agent(stream_id: &str, input: &str) -> Result<Child, String> {
+pub async fn agent(stream_id: &str, input: &str) -> Result<Child, String> {
     run_agent(stream_id, input, "./packages/genaiscript/genaisrc/news-search.genai.mts", 10).await
 }