chore: remove stories/checker backend dead code

Remove the dead stories/checker backend tracked as design debt in CLAUDE.md:
- Delete internal/api/stories.go, stories_test.go, elaborate.go
- Delete internal/task/story.go, story_test.go
- Remove story/checker columns from storage schema and all CRUD methods
- Remove checkStoryCompletion, spawnCheckerTask, triggerStoryDeploy,
  createValidationTask, checkValidationResult, ShipStory, CheckStoryCompletion
  from executor; simplify handleRunResult
- Remove story/checker fields from task.Task (StoryID, AcceptanceCriteria,
  CheckerForTaskID, CheckerReport)
- Remove story routes and geminiBinPath from API server
- Move claudeJSONResult/extractJSON from elaborate.go to validate.go
- Rename ensureStoryBranch -> ensureBranch in ContainerRunner
- Fix git identity in bare-repo tests; fix initial-branch to use main

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

1 files changed, 0 insertions, 3 deletions

diff --git a/internal/api/taskops.go b/internal/api/taskops.go
index 881babe..254d73c 100644
--- a/internal/api/taskops.go
+++ b/internal/api/taskops.go
@@ -128,9 +128,6 @@ func (s *Server) acceptTask(ctx context.Context, id string, actor event.Actor) e
 	if err := s.store.UpdateTaskStateBy(id, task.StateCompleted, actor); err != nil {
 		return err
 	}
-	if t.StoryID != "" {
-		go s.pool.CheckStoryCompletion(ctx, t.StoryID)
-	}
 	return nil
 }