Expose the Supply run title job and cover the replacement race

POST /shopping/{weekStart}/generate now answers with title_job_id, and
Push to Calendar's supply_run carries it too, so a client can follow the
title_supply_run job through GET /jobs/{id}, including a title_failed
failure. It is null when the list already has its title or was not
generated.

Add a regression test that replaces the week's list after archive_title
answers but before the title is stored: the old job fails title_failed
and the replacement stays untitled.

Maestro task a55adc28-4d8b-4517-b1d7-dcff39ea5a09.

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

docs/ARCHITECTURE.md

@@ -1120,7 +1120,10 @@ Fake-clock tests of a schedule live in `internal/scheduler`, where
   - The week's Supply run (Feature 17) is made from a pushed plan: after
     a successful `Push`, the handler runs `shopping.GeneratePushed` for
     the week at the plan revision `Push` pushed, and the 200 answer
-    carries `supply_run: {status, error}`. `status` is `generated`;
+    carries `supply_run: {status, error, title_job_id}`. `title_job_id` is
+    the `title_supply_run` job titling a generated list, as for `POST
+    /shopping/{weekStart}/generate`; null when the list already has its
+    title or was not generated. `status` is `generated`;
     `archived` when the week's Supply run is in the Supply archive and was
     left as it was; or `failed` — error `plan_changed` (retryable, logged
     as a warning) when the plan was edited between the push and
@@ -1143,8 +1146,12 @@ Fake-clock tests of a schedule live in `internal/scheduler`, where
   when the week has no Supply run, 400 `invalid_week`.
 - `POST /api/v1/shopping/{weekStart}/generate` makes or remakes the list
   through `shopping.Generate` and answers with the same shape plus
-  `skipped: [{date, dinner_id, dinner_name, reason}]`. 404 when the week
+  `skipped: [{date, dinner_id, dinner_name, reason}]` and
-  has no plan, 409 `archived` when its list is in the Supply archive.
+  `title_job_id`, the `title_supply_run` job titling the list, which
+  `GET /api/v1/jobs/{id}` reports on (failed `title_failed` when the title
+  could not be written); null when the list already has its title. 404
+  when the week has no plan, 409 `archived` when its list is in the Supply
+  archive.
 - `POST /api/v1/shopping/{weekStart}/send-chat` (CSRF-checked) takes
   `{}` or `{"resend": true}` and posts the Supply run to Google Chat
   through `chat.PostSupplyRun`, in the week's thread: "Supply run · " and

internal/server/plans.go

@@ -111,10 +111,13 @@ type pushedPlan struct {
 // plan Calendar does not show and pushing again makes it; or
 // supply_run_failed when it could not be made, and POST
 // /shopping/{weekStart}/generate makes it again. error is null when status
-// is generated.
+// is generated. title_job_id is the job titling a generated Supply run,
+// which GET /jobs/{id} reports on; null when it already has its title or
+// was not generated.
 type pushedSupplyRun struct {
-	Status string    `json:"status"`
+	Status     string    `json:"status"`
-	Error  *apiError `json:"error"`
+	Error      *apiError `json:"error"`
+	TitleJobID *string   `json:"title_job_id"`
 }
 
 // postPlanPush pushes the week's plan to the chosen Google calendar
@@ -143,7 +146,9 @@ func postPlanPush(logger *slog.Logger, svc *plan.Service, shop *shopping.Service
 		// gone.
 		ctx := context.WithoutCancel(r.Context())
 		run := pushedSupplyRun{Status: "generated"}
-		if _, err := shop.GeneratePushed(ctx, week, revision); errors.Is(err, shopping.ErrFrozen) {
+		if g, err := shop.GeneratePushed(ctx, week, revision); err == nil {
+			run.TitleJobID = g.TitleJobID
+		} else if errors.Is(err, shopping.ErrFrozen) {
 			logger.InfoContext(ctx, "Supply run in the Supply archive left as it was after Push to Calendar", "week", week.String())
 			run = pushedSupplyRun{Status: "archived", Error: &apiError{Code: "archived", Message: err.Error()}}
 		} else if errors.Is(err, shopping.ErrPlanChanged) {
@@ -153,7 +158,7 @@ func postPlanPush(logger *slog.Logger, svc *plan.Service, shop *shopping.Service
 				Message:   "the plan is on Calendar as pushed, but it was edited before its Supply run was made, so no Supply run was made from it; push again",
 				Retryable: true,
 			}}
-		} else if err != nil {
+		} else {
 			logger.ErrorContext(ctx, "generate Supply run after Push to Calendar", "week", week.String(), "error", err)
 			run = pushedSupplyRun{Status: "failed", Error: &apiError{
 				Code:      "supply_run_failed",

internal/server/shopping.go

@@ -60,10 +60,13 @@ type supplyRunItem struct {
 }
 
 // generatedSupplyRun is the POST /shopping/{weekStart}/generate answer:
-// the Supply run as made, and the plan days with nothing to shop for.
+// the Supply run as made, the plan days with nothing to shop for, and the
+// title_job_id of the job titling it, which GET /jobs/{id} reports on;
+// null when the Supply run already has its title.
 type generatedSupplyRun struct {
 	supplyRun
-	Skipped []shopping.SkippedDay `json:"skipped"`
+	Skipped    []shopping.SkippedDay `json:"skipped"`
+	TitleJobID *string               `json:"title_job_id"`
 }
 
 // sendChatRequest is the POST /shopping/{weekStart}/send-chat body:
@@ -108,7 +111,7 @@ func getSupplyRun(logger *slog.Logger, svc *shopping.Service) http.HandlerFunc {
 }
 
 // postSupplyRunGenerate makes, or remakes, the week's Supply run from its
-// plan and answers with it and the plan days it skipped.
+// plan and answers with it, the plan days it skipped and its title job.
 func postSupplyRunGenerate(logger *slog.Logger, svc *shopping.Service) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		week, ok := weekStartOrFail(w, r, logger)
@@ -129,7 +132,7 @@ func postSupplyRunGenerate(logger *slog.Logger, svc *shopping.Service) http.Hand
 		if skipped == nil {
 			skipped = []shopping.SkippedDay{}
 		}
-		writeJSON(w, r, logger, http.StatusOK, generatedSupplyRun{supplyRun: out, Skipped: skipped})
+		writeJSON(w, r, logger, http.StatusOK, generatedSupplyRun{supplyRun: out, Skipped: skipped, TitleJobID: g.TitleJobID})
 	}
 }
 

internal/server/shopping_test.go

@@ -186,7 +186,7 @@ func TestSupplyRunShape(t *testing.T) {
 	if status != http.StatusOK {
 		t.Fatalf("generate = %d %v", status, raw)
 	}
-	wantTop := []string{"chat_send_unconfirmed_at", "groups", "label", "needed_count", "sent_to_chat_at", "skipped", "status", "title", "total_count", "weekStart"}
+	wantTop := []string{"chat_send_unconfirmed_at", "groups", "label", "needed_count", "sent_to_chat_at", "skipped", "status", "title", "title_job_id", "total_count", "weekStart"}
 	if got := keys(raw); !reflect.DeepEqual(got, wantTop) {
 		t.Errorf("generate fields = %v, want %v", got, wantTop)
 	}
@@ -199,7 +199,7 @@ func TestSupplyRunShape(t *testing.T) {
 	if status != http.StatusOK {
 		t.Fatalf("GET = %d %v", status, raw)
 	}
-	if k := keys(raw); !reflect.DeepEqual(k, slices.DeleteFunc(slices.Clone(wantTop), func(s string) bool { return s == "skipped" })) {
+	if k := keys(raw); !reflect.DeepEqual(k, slices.DeleteFunc(slices.Clone(wantTop), func(s string) bool { return s == "skipped" || s == "title_job_id" })) {
 		t.Errorf("GET fields = %v", k)
 	}
 	group := raw["groups"].([]any)[0].(map[string]any)
@@ -376,8 +376,12 @@ func TestPushPlanMakesSupplyRun(t *testing.T) {
 	if rec.Code != http.StatusOK || body["status"] != "synced" {
 		t.Fatalf("push = %d %s", rec.Code, rec.Body)
 	}
-	if want := map[string]any{"status": "generated", "error": nil}; !reflect.DeepEqual(body["supply_run"], want) {
+	run, _ := body["supply_run"].(map[string]any)
-		t.Errorf("supply_run = %v, want %v", body["supply_run"], want)
+	if k := keys(run); run["status"] != "generated" || run["error"] != nil || !reflect.DeepEqual(k, []string{"error", "status", "title_job_id"}) {
+		t.Errorf("supply_run = %v, want generated with no error", run)
+	}
+	if job := titleJob(t, e, run["title_job_id"]); job["status"] != "queued" {
+		t.Errorf("title job = %v, want queued: no runner in this test", job)
 	}
 	var l supplyRunJSON
 	if status, got := callShopping(t, e, http.MethodGet, shoppingPath+"2026-10-12", "", &l); status != http.StatusOK {
@@ -467,9 +471,11 @@ func TestPushPlanDoesNotWaitForTitle(t *testing.T) {
 	if rec.Code != http.StatusOK || body["status"] != "synced" {
 		t.Fatalf("push = %d %s", rec.Code, rec.Body)
 	}
-	if want := map[string]any{"status": "generated", "error": nil}; !reflect.DeepEqual(body["supply_run"], want) {
+	run, _ := body["supply_run"].(map[string]any)
-		t.Errorf("supply_run = %v, want %v", body["supply_run"], want)
+	if run["status"] != "generated" || run["error"] != nil {
+		t.Errorf("supply_run = %v, want generated with no error", run)
 	}
+	titleJobID, _ := run["title_job_id"].(string)
 	held.waitEntered(t)
 	var l supplyRunJSON
 	callShopping(t, e, http.MethodGet, shoppingPath+"2026-10-12", "", &l)
@@ -478,6 +484,7 @@ func TestPushPlanDoesNotWaitForTitle(t *testing.T) {
 	}
 
 	close(held.release)
+	wantTitleJobSucceeded(t, e, titleJobID)
 	if got := e.waitTitled(t); got != "Chili and Friends" {
 		t.Errorf("title = %q, want the title job's", got)
 	}
@@ -493,7 +500,8 @@ func TestSupplyRunGenerateDoesNotWaitForTitle(t *testing.T) {
 	e.startRunner(t)
 
 	var l supplyRunJSON
-	if status, body := callShopping(t, e, http.MethodPost, shoppingPath+"2026-10-12/generate", "", &l); status != http.StatusOK {
+	status, body := callShopping(t, e, http.MethodPost, shoppingPath+"2026-10-12/generate", "", &l)
+	if status != http.StatusOK {
 		t.Fatalf("generate = %d %v", status, body)
 	}
 	if l.Title != nil {
@@ -502,12 +510,66 @@ func TestSupplyRunGenerateDoesNotWaitForTitle(t *testing.T) {
 	if !reflect.DeepEqual(l.render(), weekLines) {
 		t.Errorf("generated = %v, want %v", l.render(), weekLines)
 	}
+	titleJobID, _ := body["title_job_id"].(string)
 	held.waitEntered(t)
 
 	close(held.release)
+	wantTitleJobSucceeded(t, e, titleJobID)
 	if got := e.waitTitled(t); got != "Chili and Friends" {
 		t.Errorf("title = %q, want the title job's", got)
 	}
+	if _, body := callShopping(t, e, http.MethodPost, shoppingPath+"2026-10-12/generate", "", nil); body["title_job_id"] != nil {
+		t.Errorf("remake title_job_id = %v, want null: the Supply run has its title", body["title_job_id"])
+	}
+}
+
+// TestSupplyRunGenerateTitleJobFails: a title job that cannot title the
+// Supply run is reported failed with title_failed by GET /jobs/{id}, and
+// the week's next generation answers with a new title job.
+func TestSupplyRunGenerateTitleJobFails(t *testing.T) {
+	t.Parallel()
+	e := newPlansRouter(t)
+	e.groundWeek(t)
+	e.startRunner(t)
+
+	_, body := callShopping(t, e, http.MethodPost, shoppingPath+"2026-10-12/generate", "", nil)
+	first := titleJob(t, e, body["title_job_id"])
+	job := waitJob(t, e.h, first["id"].(string))
+	if job["status"] != "failed" || job["error"] != shopping.ReasonTitleFailed {
+		t.Errorf("title job = %v, want failed %s", job, shopping.ReasonTitleFailed)
+	}
+
+	_, body = callShopping(t, e, http.MethodPost, shoppingPath+"2026-10-12/generate", "", nil)
+	if second := titleJob(t, e, body["title_job_id"]); second["id"] == first["id"] {
+		t.Errorf("retry title_job_id = %v, want a new job", second["id"])
+	}
+}
+
+// titleJob returns the title_supply_run job id, as GET /jobs/{id} reports
+// it; id must be a job id string.
+func titleJob(t *testing.T, e plansEnv, id any) map[string]any {
+	t.Helper()
+	s, ok := id.(string)
+	if !ok || s == "" {
+		t.Fatalf("title_job_id = %v, want a job id", id)
+	}
+	rec, job := callDinners(t, e.h, http.MethodGet, "/api/v1/jobs/"+s, "")
+	if rec.Code != http.StatusOK || job["kind"] != shopping.KindTitleSupplyRun {
+		t.Fatalf("GET title job = %d %s, want a %s job", rec.Code, rec.Body, shopping.KindTitleSupplyRun)
+	}
+	return job
+}
+
+// wantTitleJobSucceeded waits for title job id to finish and fails t
+// unless GET /jobs/{id} reports it succeeded with the title written.
+func wantTitleJobSucceeded(t *testing.T, e plansEnv, id string) {
+	t.Helper()
+	titleJob(t, e, id)
+	job := waitJob(t, e.h, id)
+	result, _ := job["result"].(map[string]any)
+	if job["status"] != "succeeded" || result["title"] != "Chili and Friends" {
+		t.Errorf("title job = %v, want succeeded with the title", job)
+	}
 }
 
 // TestFailedPushMakesNoSupplyRun: a push Calendar refused makes no Supply
@@ -546,7 +608,7 @@ func TestPushPlanSupplyRunFails(t *testing.T) {
 		"code":      "supply_run_failed",
 		"message":   "the plan is on Calendar, but its Supply run could not be made; make it again from the Supply run",
 		"retryable": true,
-	}}
+	}, "title_job_id": nil}
 	if !reflect.DeepEqual(body["supply_run"], want) {
 		t.Errorf("supply_run = %v, want %v", body["supply_run"], want)
 	}
@@ -599,7 +661,7 @@ func TestPushPlanEditedBeforeSupplyRun(t *testing.T) {
 		"code":      "plan_changed",
 		"message":   "the plan is on Calendar as pushed, but it was edited before its Supply run was made, so no Supply run was made from it; push again",
 		"retryable": true,
-	}}
+	}, "title_job_id": nil}
 	if !reflect.DeepEqual(body["supply_run"], want) {
 		t.Errorf("supply_run = %v, want %v", body["supply_run"], want)
 	}
@@ -632,7 +694,7 @@ func TestPushPlanLeavesArchivedSupplyRun(t *testing.T) {
 		t.Fatalf("push = %d %s", rec.Code, rec.Body)
 	}
 	run, _ := body["supply_run"].(map[string]any)
-	if apiErr, _ := run["error"].(map[string]any); run["status"] != "archived" || apiErr["code"] != "archived" {
+	if apiErr, _ := run["error"].(map[string]any); run["status"] != "archived" || apiErr["code"] != "archived" || run["title_job_id"] != nil {
 		t.Errorf("supply_run = %v, want archived", body["supply_run"])
 	}
 	var l supplyRunJSON

internal/shopping/title_test.go

@@ -311,3 +311,38 @@ func TestGenerateTitleOverlapAcrossRename(t *testing.T) {
 		t.Errorf("stored title = %v, want one of the two titles", deref(got))
 	}
 }
+
+// TestGenerateTitleNotStoredOnReplacedList: a list replaced by a new
+// untitled list of the same week once archive_title has answered, before
+// its title is stored, keeps the replacement untitled; the old list's
+// title job fails, and the failure is logged.
+func TestGenerateTitleNotStoredOnReplacedList(t *testing.T) {
+	e := titleWeek(t)
+	e.model.QueueGenerate(titled("Noodles, Tacos and Chili"))
+	e.afterTitle = func() {
+		for _, stmt := range []string{
+			`DELETE FROM shopping_items WHERE group_id IN (SELECT id FROM shopping_groups WHERE list_id IN (SELECT id FROM shopping_lists WHERE week_start = ?1))`,
+			`DELETE FROM shopping_groups WHERE list_id IN (SELECT id FROM shopping_lists WHERE week_start = ?1)`,
+			`UPDATE shopping_lists SET id = 'replacement' WHERE week_start = ?1`,
+		} {
+			if _, err := e.st.Writer.Exec(stmt, week.String()); err != nil {
+				t.Error(err)
+			}
+		}
+	}
+
+	g := e.generate(t)
+	wantJob(t, e.waitTitle(t, g), jobs.StatusFailed, shopping.ReasonTitleFailed)
+
+	var id string
+	if err := e.st.Reader.QueryRow(`SELECT id FROM shopping_lists WHERE week_start = ?`, week.String()).Scan(&id); err != nil {
+		t.Fatal(err)
+	}
+	if id != "replacement" || id == g.List.ID {
+		t.Fatalf("week's list = %s, want the replacement of %s", id, g.List.ID)
+	}
+	wantUntitled(t, "replacement's title", e.storedTitle(t))
+	if !strings.Contains(e.log.String(), "the Supply run was frozen or replaced before its title was stored") {
+		t.Errorf("log lacks the failure:\n%s", e.log.String())
+	}
+}