Function dispatch_tool 

pub fn dispatch_tool(
    name: &str,
    input: &Value,
    git_ops: &dyn GitOps,
    context: &AnnotationContext,
    collected_regions: &mut Vec<RegionAnnotation>,
    collected_cross_cutting: &mut Vec<CrossCuttingConcern>,
) -> Result<String, AgentError>

Dispatch a tool call by name, returning the result string.