feat(protocol): add Paste request type for bracketed-paste events

feat(engine): summarize agent completion progress in UI notifications

feat(main): enable and disable bracketed paste support in terminal

fix(app_config): store API key from file as fallback for Claude provider

refactor(workflow): remove unnecessary card separator in workflow panel

src/app/workflow/engine.rs

@@ -278,18 +278,29 @@ fn spawn_single_agent(
 
     // Notify UI: agent completed or failed
     if let Some(f) = live {
+        let summary_from = |text: &str| {
+            text.lines()
+                .next()
+                .unwrap_or(text)
+                .chars()
+                .take(80)
+                .collect::<String>()
+        };
         match &result {
-            Ok(_) => f(
-                agent_id.to_string(),
-                agent_name.to_string(),
-                AgentStatus {
-                    state: AgentState::Completed,
-                    started_at: Some(started_at),
-                    completed_at: Some(completed_at),
-                    error: None,
-                    progress: None,
-                },
-            ),
+            Ok(text) => {
+                let summary = summary_from(text);
+                f(
+                    agent_id.to_string(),
+                    agent_name.to_string(),
+                    AgentStatus {
+                        state: AgentState::Completed,
+                        started_at: Some(started_at),
+                        completed_at: Some(completed_at),
+                        error: None,
+                        progress: Some(summary),
+                    },
+                )
+            }
             Err(e) => f(
                 agent_id.to_string(),
                 agent_name.to_string(),