refactor(tools): slim intervals_list_events payload, align error shape

Project events to {id, start_date_local, name, moving_time,
icu_training_load} so the LLM sees identifiable workouts without
workout_doc and other bloat. Rename delete error field message ->
details to match the convention in intervals_create_workout.

Author: yerzhansa

src/agent/tools.ts

@@ -329,7 +329,13 @@ function createIntervalsTools(
           category: ["WORKOUT"],
         });
         if (!result.ok) return { error: result.error.kind };
-        return result.value;
+        return result.value.map((e) => ({
+          id: e.id,
+          start_date_local: e.start_date_local,
+          name: e.name,
+          moving_time: e.moving_time,
+          icu_training_load: e.icu_training_load,
+        }));
       },
     }),
 
@@ -356,7 +362,7 @@ function createIntervalsTools(
         });
         if (!res.ok) {
           const body = await res.text().catch(() => "");
-          return { error: `http_${res.status}`, message: body || res.statusText };
+          return { error: `http_${res.status}`, details: body || res.statusText };
         }
         return { deleted: true };
       },

tests/helpers/mock-intervals.ts

@@ -355,8 +355,7 @@ export function createMockIntervalsServer(options: MockIntervalsOptions = {}) {
       return HttpResponse.json({ id: eventId, ...body }, { status: 200 });
     }),
 
-    // GET /api/v1/athlete/:id/events — list scheduled events (filters created workouts
-    // by optional oldest/newest query params; ignores category since we only emit WORKOUT)
+    // GET /api/v1/athlete/:id/events — list scheduled events
     http.get("https://intervals.icu/api/v1/athlete/:id/events", ({ request }) => {
       const url = new URL(request.url);
       const oldest = url.searchParams.get("oldest");
@@ -372,8 +371,7 @@ export function createMockIntervalsServer(options: MockIntervalsOptions = {}) {
       return HttpResponse.json(filtered);
     }),
 
-    // DELETE /api/v1/athlete/:id/events/:eventId — delete scheduled event; honors
-    // ?notBefore=YYYY-MM-DD by rejecting when the event's date is earlier.
+    // DELETE /api/v1/athlete/:id/events/:eventId — delete scheduled event (honors ?notBefore)
     http.delete(
       "https://intervals.icu/api/v1/athlete/:id/events/:eventId",
       ({ request, params }) => {