fix(worktree): log creation steps and stop swallowing errors

packages/core/src/task-detail/workspaceSetupSaga.test.ts

@@ -61,7 +61,7 @@ describe("WorkspaceSetupSaga.setupWorkspace", () => {
 
     expect(result).toEqual({
       success: false,
-      error: "Failed to set up workspace",
+      error: "boom",
     });
     expect(executor.ensureWorkspace).not.toHaveBeenCalled();
   });

packages/core/src/task-detail/workspaceSetupSaga.ts

@@ -39,8 +39,9 @@ export class WorkspaceSetupSaga {
       this.log.info("Workspace setup complete", { taskId, path });
       return { success: true };
     } catch (error) {
-      this.log.error("Failed to set up workspace", { error });
-      return { success: false, error: "Failed to set up workspace" };
+      this.log.error("Failed to set up workspace", { taskId, path, error });
+      const message = error instanceof Error ? error.message : String(error);
+      return { success: false, error: message };
     }
   }
 }

packages/git/src/queries.ts

@@ -1077,12 +1077,14 @@ export async function fetchRef(
   git: GitLike,
   remote: string,
   ref: string,
+  options?: { onError?: (message: string) => void },
 ): Promise<boolean> {
   try {
     // `--` keeps a ref beginning with `-` from being parsed as an option.
     await git.raw(["fetch", "--quiet", "--no-tags", remote, "--", ref]);
     return true;
-  } catch {
+  } catch (error) {
+    options?.onError?.(error instanceof Error ? error.message : String(error));
     return false;
   }
 }