feat: Phase 5 — story elaboration endpoint, approve flow, branch creation

- POST /api/stories/elaborate: runs Claude/Gemini against project LocalPath
  to produce a structured story plan (name, branch_name, tasks, validation)
- POST /api/stories/approve: creates story + sequentially-wired tasks/subtasks
  from the elaborate output and pushes the story branch to origin
- createStoryBranch helper: git checkout -b + push -u origin
- Tests: TestBuildStoryElaboratePrompt, TestHandleStoryApprove_WiresDepends

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

1 files changed, 84 insertions, 0 deletions

diff --git a/internal/api/stories_test.go b/internal/api/stories_test.go
index 8516ade..cf522e1 100644
--- a/internal/api/stories_test.go
+++ b/internal/api/stories_test.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"github.com/thepeterstone/claudomator/internal/task"
@@ -118,3 +119,86 @@ func TestAddTaskToStory_AutoWiresDependsOn(t *testing.T) {
 		t.Errorf("task3.DependsOn: want [%s], got %v", task2.ID, task3.DependsOn)
 	}
 }
+
+func TestBuildStoryElaboratePrompt(t *testing.T) {
+	prompt := buildStoryElaboratePrompt()
+	checks := []struct {
+		label string
+		want  string
+	}{
+		{"schema: name field", `"name"`},
+		{"schema: branch_name field", `"branch_name"`},
+		{"schema: tasks field", `"tasks"`},
+		{"schema: validation field", `"validation"`},
+		{"rule: git push", "git push origin"},
+		{"rule: sequential subtasks", "sequentially"},
+		{"rule: specific file paths", "file paths"},
+	}
+	for _, c := range checks {
+		if !strings.Contains(prompt, c.want) {
+			t.Errorf("%s: prompt should contain %q", c.label, c.want)
+		}
+	}
+}
+
+func TestHandleStoryApprove_WiresDepends(t *testing.T) {
+	srv, _ := testServer(t)
+
+	body := `{
+		"name": "My Story",
+		"branch_name": "story/my-story",
+		"tasks": [
+			{"name": "Task 1", "instructions": "do task 1", "subtasks": []},
+			{"name": "Task 2", "instructions": "do task 2", "subtasks": []},
+			{"name": "Task 3", "instructions": "do task 3", "subtasks": []}
+		],
+		"validation": {"type": "build", "steps": ["go build ./..."], "success_criteria": "compiles"}
+	}`
+	req := httptest.NewRequest("POST", "/api/stories/approve", bytes.NewBufferString(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	srv.mux.ServeHTTP(w, req)
+
+	if w.Code != http.StatusCreated {
+		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
+	}
+
+	var resp struct {
+		Story   task.Story `json:"story"`
+		TaskIDs []string   `json:"task_ids"`
+	}
+	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if len(resp.TaskIDs) != 3 {
+		t.Fatalf("expected 3 task IDs, got %d", len(resp.TaskIDs))
+	}
+	if resp.Story.Name != "My Story" {
+		t.Errorf("story name: want 'My Story', got %q", resp.Story.Name)
+	}
+
+	// Verify depends_on chain via the store.
+	store := srv.store
+	task1, err := store.GetTask(resp.TaskIDs[0])
+	if err != nil {
+		t.Fatalf("GetTask[0]: %v", err)
+	}
+	task2, err := store.GetTask(resp.TaskIDs[1])
+	if err != nil {
+		t.Fatalf("GetTask[1]: %v", err)
+	}
+	task3, err := store.GetTask(resp.TaskIDs[2])
+	if err != nil {
+		t.Fatalf("GetTask[2]: %v", err)
+	}
+
+	if len(task1.DependsOn) != 0 {
+		t.Errorf("task1.DependsOn: want [], got %v", task1.DependsOn)
+	}
+	if len(task2.DependsOn) != 1 || task2.DependsOn[0] != task1.ID {
+		t.Errorf("task2.DependsOn: want [%s], got %v", task1.ID, task2.DependsOn)
+	}
+	if len(task3.DependsOn) != 1 || task3.DependsOn[0] != task2.ID {
+		t.Errorf("task3.DependsOn: want [%s], got %v", task2.ID, task3.DependsOn)
+	}
+}