docs: align historical plans/specs with renamed identifiers (roundTrip -> execute, log schema)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/superpowers/specs/2026-07-27-workout-not-found-design.md

@@ -42,7 +42,7 @@ dispatcher that `get_workout_by_id` goes through) gains a check: if the caught e
 
 - `wireResponse` gains `NotFound bool `json:"not_found,omitempty"``.
 - A new sentinel: `var ErrNotFound = errors.New("garmin: resource not found")`.
-- `roundTrip`: when `resp.Error != "" && resp.NotFound`, the returned error wraps `ErrNotFound`
+- `execute`: when `resp.Error != "" && resp.NotFound`, the returned error wraps `ErrNotFound`
   (`fmt.Errorf("%s: %s: %w", cmdName, resp.Error, ErrNotFound)`), so callers can
   `errors.Is(err, garmin.ErrNotFound)` regardless of which method was called.
 
@@ -96,7 +96,7 @@ no shape change -- a test simulating a 404 just sets the mapped error to
 - `internal/garmin/pyscript/tests/test_wrapper.py`: a new test mirroring the existing
   `test_call_propagates_garminconnect_exception_as_error`, but raising
   `GarminConnectNotFoundError` and asserting the response includes `"not_found": true`.
-- `internal/garmin` (Go): a test asserting `roundTrip` wraps the error with `ErrNotFound` when
+- `internal/garmin` (Go): a test asserting `execute` wraps the error with `ErrNotFound` when
   the wire response sets `not_found: true`.
 - `internal/store`: extend the existing `ActivitiesMissingWorkout` test (or add a new one) with a
   fixture that has `workout_not_found_at` set, asserting it's excluded from both