feat: introduce workflow management tools and commands

- Added new workflow commands: `/workflow` to open the workflow panel and `/workflow run <prompt>` to execute workflows.
- Implemented `spawn_agents` and `spawn_pipeline` tools for parallel and sequential task execution, respectively.
- Enhanced workflow engine to handle real-time agent status updates and display in the UI.
- Updated workflow panel to show agent statuses, findings count, and session counters.
- Refactored existing code to integrate new workflow functionalities and improve overall structure.

src/controller/command.rs

@@ -25,6 +25,10 @@ pub enum Command {
     },
     ModelList,
     Compact,
+    WorkflowOpen,
+    WorkflowRun {
+        script: String,
+    },
     Unknown(String),
 }
 
@@ -88,6 +92,14 @@ pub fn parse_command(text: &str) -> Command {
         }
         "/model" => Command::ModelList,
         "/compact" => Command::Compact,
+        "/workflow" if arg1.is_empty() => Command::WorkflowOpen,
+        "/workflow" if arg1 == "run" && !arg2.is_empty() => Command::WorkflowRun {
+            script: arg2.to_string(),
+        },
+        "/workflow" if arg1 == "run" => Command::WorkflowOpen,
+        "/workflow" => Command::WorkflowRun {
+            script: arg1.to_string(),
+        },
         _ => Command::Unknown(cmd.to_string()),
     }
 }