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, 42 deletions

diff --git a/internal/task/story_test.go b/internal/task/story_test.go
deleted file mode 100644
index 38d0290..0000000
--- a/internal/task/story_test.go
+++ /dev/null
@@ -1,42 +0,0 @@
-package task
-
-import "testing"
-
-func TestValidStoryTransition_Valid(t *testing.T) {
-	cases := []struct {
-		from StoryState
-		to   StoryState
-	}{
-		{StoryPending, StoryInProgress},
-		{StoryInProgress, StoryShippable},
-		{StoryInProgress, StoryNeedsFix},
-		{StoryNeedsFix, StoryInProgress},
-		{StoryShippable, StoryDeployed},
-		{StoryDeployed, StoryValidating},
-		{StoryValidating, StoryReviewReady},
-		{StoryValidating, StoryNeedsFix},
-	}
-	for _, tc := range cases {
-		if !ValidStoryTransition(tc.from, tc.to) {
-			t.Errorf("expected valid transition %s → %s", tc.from, tc.to)
-		}
-	}
-}
-
-func TestValidStoryTransition_Invalid(t *testing.T) {
-	cases := []struct {
-		from StoryState
-		to   StoryState
-	}{
-		{StoryPending, StoryDeployed},
-		{StoryReviewReady, StoryPending},
-		{StoryReviewReady, StoryInProgress},
-		{StoryReviewReady, StoryShippable},
-		{StoryShippable, StoryPending},
-	}
-	for _, tc := range cases {
-		if ValidStoryTransition(tc.from, tc.to) {
-			t.Errorf("expected invalid transition %s → %s", tc.from, tc.to)
-		}
-	}
-}