Add idea actions: add to Quest log and cook tonight (Feature 18)

POST /api/v1/ideas/{jobId}/items/{i}/quest-log adds idea i of a
succeeded ideas job to the Quest log as a dinner grounded in the idea's
own recipe, with origin ingredients or quick, or answers the dinner it
repeats as it is (the Regular dedupe rule), so repeating the call is
idempotent. POST .../cook-tonight does the same, then puts the dinner on
today (household timezone) of this week's plan through plan.Service.Swap;
with no plan for the week it answers 409 no_plan and changes nothing.

Maestro task 54dcd487-1597-4a91-8493-97f3a7635e2d.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/ideas/ideas.go

@@ -92,6 +92,7 @@ type QuickGenerator func(ctx context.Context, scope string, in skills.QuickIdeas
 type Service struct {
 	st       *store.Store
 	grounder *recipes.Grounder
+	runner   *jobs.Runner
 	generate Generator
 	quick    QuickGenerator
 	logger   *slog.Logger
@@ -120,7 +121,7 @@ func NewService(st *store.Store, grounder *recipes.Grounder, generate Generator,
 	case logger == nil:
 		return nil, errors.New("ideas: nil logger")
 	}
-	s := &Service{st: st, grounder: grounder, generate: generate, quick: quick, logger: logger}
+	s := &Service{st: st, grounder: grounder, runner: runner, generate: generate, quick: quick, logger: logger}
 	var err error
 	if s.job, err = register(runner, KindFromIngredients, s.run, withoutIdeas[Result]); err != nil {
 		return nil, err
@@ -589,3 +590,73 @@ func quickIdeaOf(idea skills.QuickIdea, gr recipes.Grounded) QuickIdea {
 		SiteName:     gr.SiteName,
 	}
 }
+
+// Origins of a dinner made from an idea (the dinners.origin column).
+const (
+	// OriginIngredients is an idea from Cook from what I have.
+	OriginIngredients = "ingredients"
+	// OriginQuick is an idea from Quick dinners.
+	OriginQuick = "quick"
+)
+
+// ErrIdeaNotFound is an idea the household cannot act on: an unknown job,
+// a job that does not find ideas, a failed job (which shows no ideas), or
+// an index past the job's ideas.
+var ErrIdeaNotFound = errors.New("idea not found")
+
+// ErrIdeasNotReady is an idea of a job still queued or running. Its ideas
+// may still move: an idea that grounds later is put back in its place
+// before those shown already, so an index names an idea only once the job
+// has succeeded.
+var ErrIdeasNotReady = errors.New("the ideas are still being found; act on one when the job has succeeded")
+
+// Chosen is the idea the household acts on: its name, the recipe it was
+// grounded in, and the origin of a dinner made from it.
+type Chosen struct {
+	Name     string
+	RecipeID string
+	Origin   string
+}
+
+// Idea returns idea i, counted from 0, of the succeeded job jobID, as its
+// stored result shows it: a dinner made from it uses the recipe it was
+// grounded in, never grounding it again. A job still queued or running is
+// ErrIdeasNotReady; any idea not shown by a succeeded KindFromIngredients
+// or KindQuick job is ErrIdeaNotFound.
+func (s *Service) Idea(ctx context.Context, jobID string, i int) (Chosen, error) {
+	job, err := s.runner.Get(ctx, jobID)
+	if errors.Is(err, jobs.ErrNotFound) {
+		return Chosen{}, ErrIdeaNotFound
+	}
+	if err != nil {
+		return Chosen{}, fmt.Errorf("ideas: read job: %w", err)
+	}
+	if job.Kind != KindFromIngredients && job.Kind != KindQuick {
+		return Chosen{}, ErrIdeaNotFound
+	}
+	switch job.Status {
+	case jobs.StatusQueued, jobs.StatusRunning:
+		return Chosen{}, ErrIdeasNotReady
+	case jobs.StatusSucceeded:
+	default:
+		return Chosen{}, ErrIdeaNotFound
+	}
+	if job.Kind == KindQuick {
+		var res QuickResult
+		if err := json.Unmarshal(job.Result, &res); err != nil {
+			return Chosen{}, fmt.Errorf("ideas: decode %s result: %w", job.Kind, err)
+		}
+		if i < 0 || i >= len(res.Ideas) {
+			return Chosen{}, ErrIdeaNotFound
+		}
+		return Chosen{Name: res.Ideas[i].Name, RecipeID: res.Ideas[i].RecipeID, Origin: OriginQuick}, nil
+	}
+	var res Result
+	if err := json.Unmarshal(job.Result, &res); err != nil {
+		return Chosen{}, fmt.Errorf("ideas: decode %s result: %w", job.Kind, err)
+	}
+	if i < 0 || i >= len(res.Ideas) {
+		return Chosen{}, ErrIdeaNotFound
+	}
+	return Chosen{Name: res.Ideas[i].Name, RecipeID: res.Ideas[i].RecipeID, Origin: OriginIngredients}, nil
+}