Wire plan_ready, list_ready, new_suggestions and Send to Google Chat

Connect the features to the notification outbox so real events notify,
each stored by the new notify.EmitTx in the transaction of the change it
is about (Wake after commit):

- plan_ready:{weekStart} (/plan) when a draft job stores the AI's draft;
  a redraft shares the key and a manual swap never emits. The title reads
  "Next week's plan is ready" for the coming week.
- list_ready:{weekStart} (/plan/shopping) when a week's Supply run is
  first created, by generate or after Push to Calendar.
- new_suggestions:{batchId} (/discover) when a scheduled or manual batch
  ends done with cards; replenish batches never notify.
- plan.Service.EmitDayOfReminder(date) emits day_of_reminder:{date} for
  the Feature 20 scheduler.

Add POST /api/v1/shopping/{weekStart}/send-chat: shopping.SendToChat posts
the dinners with needed items and a link through chat.PostSupplyRun,
records sent_to_chat_at, and is idempotent per week unless
{"resend": true}. The Supply run's Send to Google Chat button calls it
("Send again" once sent) and shows failures in an ErrorBanner; the unused
Unavailable placeholder is removed.

Task: f0cd9d50-9c11-41be-a945-7bae9f5f28a4

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

internal/suggest/suggest_test.go

@@ -23,6 +23,8 @@ import (
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/gcal"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/notify"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/notify/notifytest"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/plan"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/recipes"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/recipes/recipestest"
@@ -121,7 +123,7 @@ func newEnv(t *testing.T) *env {
 	if err != nil {
 		t.Fatal(err)
 	}
-	e.svc, err = suggest.NewService(st, g, suggester, e.runner, logger)
+	e.svc, err = suggest.NewService(st, g, suggester, e.runner, notifytest.New(t, st), logger)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -401,6 +403,57 @@ func TestBatchStoresGroundedSideQuests(t *testing.T) {
 	}
 }
 
+// TestBatchEmitsNewSuggestions: a scheduled or manual batch that adds Side
+// quests stores new_suggestions keyed by the batch, naming them; a
+// replenish batch, or one that adds none, stores nothing.
+func TestBatchEmitsNewSuggestions(t *testing.T) {
+	for _, tc := range []struct {
+		trigger string
+		grounds bool
+		notify  bool
+	}{
+		{suggest.TriggerScheduled, true, true},
+		{suggest.TriggerManual, true, true},
+		{suggest.TriggerReplenish, true, false},
+		{suggest.TriggerManual, false, false},
+	} {
+		t.Run(fmt.Sprintf("%s grounds %v", tc.trigger, tc.grounds), func(t *testing.T) {
+			e := newEnv(t)
+			e.start(t)
+			if tc.grounds {
+				e.recipe(t, "Chicken Shawarma Bowls")
+				e.recipe(t, "Chili Verde")
+			}
+			e.reply(
+				sideQuest("Chicken Shawarma Bowls", "Spiced chicken, like your Chicken Fajitas.", "Chicken Fajitas"),
+				sideQuest("Chili Verde", "Your Beef Chili gone green.", "Beef Chili"),
+			)
+			b, err := e.svc.StartBatch(t.Context(), tc.trigger)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if job := e.waitJob(t, b.JobID); job.Status != jobs.StatusSucceeded {
+				t.Fatalf("batch job %s", job.Status)
+			}
+			rows := notifytest.Rows(t, e.st, notify.NewSuggestions)
+			if !tc.notify {
+				if len(rows) != 0 {
+					t.Errorf("new_suggestions rows = %+v, want none", rows)
+				}
+				return
+			}
+			if len(rows) != 1 {
+				t.Fatalf("new_suggestions rows = %+v, want one on push", rows)
+			}
+			r := rows[0]
+			if r.Key != "new_suggestions:"+b.ID || r.Channel != notify.ChannelPush || r.Payload.URL != "/discover" ||
+				r.Payload.Title != "New Side quests are in" || r.Payload.Body != "Chicken Shawarma Bowls, Chili Verde" || r.Payload.Week == "" {
+				t.Errorf("new_suggestions row = %+v, want key new_suggestions:%s naming the Side quests, /discover", r, b.ID)
+			}
+		})
+	}
+}
+
 func TestBatchKeepsAtMostBatchSize(t *testing.T) {
 	e := newEnv(t)
 	e.start(t)
@@ -929,7 +982,7 @@ func TestLaterBatchNeverResuggestsRenamedDrop(t *testing.T) {
 	fail := func(context.Context, string, skills.WeekRequest) (skills.Week, error) {
 		return skills.Week{}, errors.New("no draft in this test")
 	}
-	planSvc, err := plan.NewService(e.st, fail, e.runner, noCalendar{}, &url.URL{Scheme: "https", Host: "meals.example.com"}, logger)
+	planSvc, err := plan.NewService(e.st, fail, e.runner, noCalendar{}, notifytest.New(t, e.st), &url.URL{Scheme: "https", Host: "meals.example.com"}, logger)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1151,6 +1204,9 @@ func TestBatchJobFailsWhenRecordingItsEndFails(t *testing.T) {
 	if got := e.batchStatus(t, b.ID); got != suggest.BatchFailed {
 		t.Errorf("batch status = %s with its job failed, want failed", got)
 	}
+	if rows := notifytest.Rows(t, e.st, notify.NewSuggestions); len(rows) != 0 {
+		t.Errorf("new_suggestions rows of a batch whose end was not recorded = %+v, want none", rows)
+	}
 }
 
 func TestBatchRecoversWhenRecordingItsEndAndItsJobsEndFail(t *testing.T) {
@@ -1284,7 +1340,7 @@ func TestBlockedBatchEndDoesNotHoldShutdown(t *testing.T) {
 	refuse := func(context.Context, string, skills.SideQuestsRequest) (skills.SideQuests, error) {
 		return skills.SideQuests{}, errors.New("not wanted")
 	}
-	svc, err := suggest.NewService(e.st, e.grounder, refuse, next, logger)
+	svc, err := suggest.NewService(e.st, e.grounder, refuse, next, notifytest.New(t, e.st), logger)
 	if err != nil {
 		t.Fatal(err)
 	}