Story 42: Deterministic worktree management via REST/MCP API

Add REST and MCP endpoints for creating, listing, and removing worktrees.
Includes worktree lifecycle management and cleanup operations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/http/agents.rs

@@ -1,6 +1,7 @@
 use crate::config::ProjectConfig;
 use crate::http::context::{AppContext, OpenApiResult, bad_request};
-use poem_openapi::{Object, OpenApi, Tags, payload::Json};
+use crate::worktree;
+use poem_openapi::{Object, OpenApi, Tags, param::Path, payload::Json};
 use serde::Serialize;
 use std::sync::Arc;
 
@@ -40,6 +41,25 @@ struct AgentConfigInfoResponse {
     max_budget_usd: Option<f64>,
 }
 
+#[derive(Object)]
+struct CreateWorktreePayload {
+    story_id: String,
+}
+
+#[derive(Object, Serialize)]
+struct WorktreeInfoResponse {
+    story_id: String,
+    worktree_path: String,
+    branch: String,
+    base_branch: String,
+}
+
+#[derive(Object, Serialize)]
+struct WorktreeListEntry {
+    story_id: String,
+    path: String,
+}
+
 pub struct AgentsApi {
     pub ctx: Arc<AppContext>,
 }
@@ -177,4 +197,70 @@ impl AgentsApi {
                 .collect(),
         ))
     }
+
+    /// Create a git worktree for a story under .story_kit/worktrees/{story_id}.
+    #[oai(path = "/agents/worktrees", method = "post")]
+    async fn create_worktree(
+        &self,
+        payload: Json<CreateWorktreePayload>,
+    ) -> OpenApiResult<Json<WorktreeInfoResponse>> {
+        let project_root = self
+            .ctx
+            .agents
+            .get_project_root(&self.ctx.state)
+            .map_err(bad_request)?;
+
+        let info = self
+            .ctx
+            .agents
+            .create_worktree(&project_root, &payload.0.story_id)
+            .await
+            .map_err(bad_request)?;
+
+        Ok(Json(WorktreeInfoResponse {
+            story_id: payload.0.story_id,
+            worktree_path: info.path.to_string_lossy().to_string(),
+            branch: info.branch,
+            base_branch: info.base_branch,
+        }))
+    }
+
+    /// List all worktrees under .story_kit/worktrees/.
+    #[oai(path = "/agents/worktrees", method = "get")]
+    async fn list_worktrees(&self) -> OpenApiResult<Json<Vec<WorktreeListEntry>>> {
+        let project_root = self
+            .ctx
+            .agents
+            .get_project_root(&self.ctx.state)
+            .map_err(bad_request)?;
+
+        let entries = worktree::list_worktrees(&project_root).map_err(bad_request)?;
+
+        Ok(Json(
+            entries
+                .into_iter()
+                .map(|e| WorktreeListEntry {
+                    story_id: e.story_id,
+                    path: e.path.to_string_lossy().to_string(),
+                })
+                .collect(),
+        ))
+    }
+
+    /// Remove a git worktree and its feature branch for a story.
+    #[oai(path = "/agents/worktrees/:story_id", method = "delete")]
+    async fn remove_worktree(&self, story_id: Path<String>) -> OpenApiResult<Json<bool>> {
+        let project_root = self
+            .ctx
+            .agents
+            .get_project_root(&self.ctx.state)
+            .map_err(bad_request)?;
+
+        let config = ProjectConfig::load(&project_root).map_err(bad_request)?;
+        worktree::remove_worktree_by_story_id(&project_root, &story_id.0, &config)
+            .await
+            .map_err(bad_request)?;
+
+        Ok(Json(true))
+    }
 }