story-kit: merge 271_story_show_assigned_agent_in_expanded_work_item_view

Adds assigned agent display to the expanded work item detail panel.
Resolved conflicts by keeping master versions of bot.rs (permission
handling), ChatInput.tsx, and fs.rs. Removed duplicate list_project_files
endpoint and tests from io.rs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/http/agents.rs

@@ -68,6 +68,7 @@ struct WorkItemContentResponse {
     content: String,
     stage: String,
     name: Option<String>,
+    agent: Option<String>,
 }
 
 /// A single test case result for the OpenAPI response.
@@ -354,13 +355,14 @@ impl AgentsApi {
             if file_path.exists() {
                 let content = std::fs::read_to_string(&file_path)
                     .map_err(|e| bad_request(format!("Failed to read work item: {e}")))?;
-                let name = crate::io::story_metadata::parse_front_matter(&content)
-                    .ok()
-                    .and_then(|m| m.name);
+                let metadata = crate::io::story_metadata::parse_front_matter(&content).ok();
+                let name = metadata.as_ref().and_then(|m| m.name.clone());
+                let agent = metadata.and_then(|m| m.agent);
                 return Ok(Json(WorkItemContentResponse {
                     content,
                     stage: stage_name.to_string(),
                     name,
+                    agent,
                 }));
             }
         }

server/src/http/io.rs

@@ -401,4 +401,5 @@ mod tests {
         let result = api.list_directory(payload).await;
         assert!(result.is_err());
     }
+
 }