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/shopping/notify_test.go

@@ -0,0 +1,169 @@
+package shopping_test
+
+import (
+	"errors"
+	"net/http"
+	"slices"
+	"testing"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/chat"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/chat/chattest"
+	"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/shopping"
+)
+
+// TestGenerateEmitsListReadyOnce: the week's first Supply run stores
+// list_ready keyed by the week, on push and Google Chat; remaking it, and
+// making it again after Push to Calendar, stores nothing more.
+func TestGenerateEmitsListReadyOnce(t *testing.T) {
+	e := newEnv(t)
+	e.dinner(t, "Beef Chili", ing{"ground beef", "1", "lb"}, ing{"onion", "1", ""})
+	e.dinner(t, "Pad Thai", ing{"rice noodles", "8", "oz"})
+	e.dinner(t, "Pot Roast")
+	e.plan(t, "Beef Chili", "Pad Thai", "Pot Roast")
+
+	if _, err := e.svc.Generate(t.Context(), mustDate("2026-10-19")); !errors.Is(err, shopping.ErrPlanNotFound) {
+		t.Fatalf("Generate of a week with no plan = %v", err)
+	}
+	if rows := notifytest.Rows(t, e.st, notify.ListReady); len(rows) != 0 {
+		t.Fatalf("list_ready rows after a failed generation = %+v, want none", rows)
+	}
+
+	e.generate(t)
+	rows := notifytest.Rows(t, e.st, notify.ListReady)
+	if len(rows) != 2 || rows[0].Channel != notify.ChannelChat || rows[1].Channel != notify.ChannelPush {
+		t.Fatalf("list_ready rows = %+v, want one on chat and one on push", rows)
+	}
+	for _, r := range rows {
+		p := r.Payload
+		if r.Key != "list_ready:2026-10-12" || p.URL != "/plan/shopping" || p.Week != "2026-10-12" ||
+			p.Title != "This week's Supply run is ready" || p.Body != "3 items to buy for 2 dinners" {
+			t.Errorf("%s row = %+v, want list_ready:2026-10-12, 3 items for 2 dinners, /plan/shopping", r.Channel, r)
+		}
+	}
+
+	e.swap(t, "2026-10-14", "Pad Thai")
+	e.swap(t, "2026-10-13", "Pot Roast")
+	e.generate(t)
+	if _, err := e.svc.GeneratePushed(t.Context(), week, planRevision(t, e)); err != nil {
+		t.Fatal(err)
+	}
+	if again := notifytest.Rows(t, e.st, notify.ListReady); !slices.Equal(again, rows) {
+		t.Errorf("list_ready rows after remaking = %+v, want the first list's only", again)
+	}
+}
+
+// planRevision is the revision of the env's plan.
+func planRevision(t *testing.T, e *env) int64 {
+	t.Helper()
+	var rev int64
+	if err := e.st.Reader.QueryRow(`SELECT revision FROM week_plans WHERE id = ?`, e.planID).Scan(&rev); err != nil {
+		t.Fatal(err)
+	}
+	return rev
+}
+
+// TestSendToChat posts the Supply run's needed items by dinner, records
+// sent_to_chat_at, sends a week once, and again only with resend.
+func TestSendToChat(t *testing.T) {
+	e := newEnv(t)
+	e.dinner(t, "Beef Chili", ing{"ground beef", "1", "lb"}, ing{"onion", "1", ""})
+	e.dinner(t, "Pad Thai", ing{"rice noodles", "8", "oz"})
+	e.plan(t, "Beef Chili", "Pad Thai")
+	l := e.generate(t).List
+	e.haveIt(t, l, "Pad Thai", "rice noodles")
+	if _, err := e.chatSvc.Put(t.Context(), chattest.Webhook, "Family"); err != nil {
+		t.Fatal(err)
+	}
+
+	sent, err := e.svc.SendToChat(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sent.SentToChatAt == nil {
+		t.Fatal("sent_to_chat_at not recorded")
+	}
+	posts := e.chat.Posts()
+	if len(posts) != 1 {
+		t.Fatalf("Google Chat got %d posts, want 1", len(posts))
+	}
+	want := chat.SupplyRunText("Week 42 · Oct 12 – 18", []chat.SupplyRunGroup{
+		{Dinner: "Beef Chili", Items: []chat.SupplyRunItem{{Name: "ground beef", Qty: "1 lb"}, {Name: "onion", Qty: "1"}}},
+		{Dinner: "Pad Thai"},
+	})
+	if posts[0].Text() != want {
+		t.Errorf("posted text = %q, want %q", posts[0].Text(), want)
+	}
+	if posts[0].Query.Get("threadKey") != chat.ThreadKey(week) {
+		t.Errorf("posted in thread %q, want %q", posts[0].Query.Get("threadKey"), chat.ThreadKey(week))
+	}
+	if got, err := e.svc.Get(t.Context(), week); err != nil || got.SentToChatAt == nil || *got.SentToChatAt != *sent.SentToChatAt {
+		t.Errorf("stored sent_to_chat_at = %v, %v, want %s", got.SentToChatAt, err, *sent.SentToChatAt)
+	}
+
+	again, err := e.svc.SendToChat(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n := len(e.chat.Posts()); n != 1 || *again.SentToChatAt != *sent.SentToChatAt {
+		t.Errorf("send again without resend: %d posts, sent_to_chat_at %s, want 1 post and %s", n, *again.SentToChatAt, *sent.SentToChatAt)
+	}
+
+	if _, err := e.st.Writer.Exec(`UPDATE shopping_lists SET title = 'Chili and noodles'`); err != nil {
+		t.Fatal(err)
+	}
+	resent, err := e.svc.SendToChat(t.Context(), week, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	posts = e.chat.Posts()
+	if len(posts) != 2 || *resent.SentToChatAt < *sent.SentToChatAt {
+		t.Fatalf("resend: %d posts, sent_to_chat_at %s, want 2 posts and a later time than %s", len(posts), *resent.SentToChatAt, *sent.SentToChatAt)
+	}
+	if want := "Supply run · Chili and noodles"; posts[1].Text()[:len(want)] != want {
+		t.Errorf("resent text = %q, want it headed by the title", posts[1].Text())
+	}
+}
+
+// TestSendToChatFailuresRecordNothing: a send with no webhook, or one
+// Google Chat refuses or does not answer, leaves sent_to_chat_at unset; a
+// week with no list, or a frozen one, is refused without posting.
+func TestSendToChatFailuresRecordNothing(t *testing.T) {
+	e := newEnv(t)
+	e.dinner(t, "Beef Chili", ing{"ground beef", "1", "lb"})
+	e.plan(t, "Beef Chili")
+
+	if _, err := e.svc.SendToChat(t.Context(), week, false); !errors.Is(err, shopping.ErrListNotFound) {
+		t.Errorf("SendToChat with no list = %v, want ErrListNotFound", err)
+	}
+	e.generate(t)
+	if _, err := e.svc.SendToChat(t.Context(), week, false); !errors.Is(err, chat.ErrNotConfigured) {
+		t.Errorf("SendToChat with no webhook = %v, want chat.ErrNotConfigured", err)
+	}
+	if _, err := e.chatSvc.Put(t.Context(), chattest.Webhook, "Family"); err != nil {
+		t.Fatal(err)
+	}
+	e.chat.SetStatus(http.StatusInternalServerError)
+	if _, err := e.svc.SendToChat(t.Context(), week, false); !errors.Is(err, chat.ErrRefused) {
+		t.Errorf("SendToChat answered 500 = %v, want chat.ErrRefused", err)
+	}
+	e.chat.Close()
+	if _, err := e.svc.SendToChat(t.Context(), week, false); !errors.Is(err, chat.ErrUnreachable) {
+		t.Errorf("SendToChat unanswered = %v, want chat.ErrUnreachable", err)
+	}
+	if l, err := e.svc.Get(t.Context(), week); err != nil || l.SentToChatAt != nil {
+		t.Errorf("sent_to_chat_at after failed sends = %v, %v, want unset", l.SentToChatAt, err)
+	}
+
+	if _, err := e.st.Writer.Exec(`UPDATE shopping_lists SET status = 'archived', frozen_at = '2026-10-19T04:05:00Z'`); err != nil {
+		t.Fatal(err)
+	}
+	posts := len(e.chat.Posts())
+	if _, err := e.svc.SendToChat(t.Context(), week, true); !errors.Is(err, shopping.ErrFrozen) {
+		t.Errorf("SendToChat of a frozen list = %v, want ErrFrozen", err)
+	}
+	if n := len(e.chat.Posts()); n != posts {
+		t.Errorf("a frozen list was posted")
+	}
+}