Fix Home dashboard integration findings (Feature 21)

- F21-01: plan_ready and list_ready links carry their week
  (/plan?week=, /plan/shopping?week=), and the Plan opens on ?week=
  and keeps it on the week shown, so an older update opens its week.
- F21-02: a failed refresh of the Rotation check shows its ErrorBanner
  beside the cached pending card instead of replacing it.
- F21-03: Home carries the household's timezone and is read again at
  its next local midnight.
- F21-04: Home counts pending Side quests through a read-only query
  (suggest.PendingCount), so reading Home never writes batches.

Task: ac3dddf0-a05f-4e43-a5ad-3105fe6bdd95

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

internal/chat/chat_test.go

@@ -342,8 +342,8 @@ func TestSendThreadsByWeek(t *testing.T) {
 		t.Errorf("plan text = %q", reqs[0].Body["text"])
 	}
 
-	// The cards' "Open" buttons link under the public URL.
-	for i, wantLink := range map[int]string{0: "https://mealquest.example/plan", 1: "https://mealquest.example/plan/shopping"} {
+	// The cards' "Open" buttons link under the public URL to the event's week.
+	for i, wantLink := range map[int]string{0: "https://mealquest.example/plan?week=2026-10-12", 1: "https://mealquest.example/plan/shopping?week=2026-10-12"} {
 		data, _ := json.Marshal(reqs[i].Body["cardsV2"])
 		var cards []cardV2
 		if err := json.Unmarshal(data, &cards); err != nil || len(cards) != 1 {

internal/chat/messages.go

@@ -2,6 +2,7 @@ package chat
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 	"time"
 
@@ -46,7 +47,7 @@ func PlanReady(week, thisWeek store.LocalDate, dinners []string) notify.Event {
 		Key:   string(notify.PlanReady) + ":" + week.String(),
 		Title: planTitle(week, thisWeek),
 		Body:  nameList(dinners),
-		URL:   "/plan",
+		URL:   "/plan?" + url.Values{"week": {week.String()}}.Encode(),
 		Week:  week,
 	}
 }
@@ -59,7 +60,7 @@ func ListReady(week store.LocalDate, needed, dinners int) notify.Event {
 		Key:   string(notify.ListReady) + ":" + week.String(),
 		Title: "This week's Supply run is ready",
 		Body:  fmt.Sprintf("%s to buy for %s", count(needed, "item", "items"), count(dinners, "dinner", "dinners")),
-		URL:   "/plan/shopping",
+		URL:   "/plan/shopping?" + url.Values{"week": {week.String()}}.Encode(),
 		Week:  week,
 	}
 }

internal/chat/messages_test.go

@@ -38,7 +38,7 @@ func TestMessages(t *testing.T) {
 			name:  "plan ready",
 			ev:    PlanReady(week, week, []string{"Tacos", "Bolognese", "Tikka masala", "Lemon orzo", "Bibimbap", "Shakshuka", "Chili"}),
 			key:   "plan_ready:2026-10-12",
-			url:   "/plan",
+			url:   "/plan?week=2026-10-12",
 			week:  "2026-10-12",
 			title: "This week's plan is ready",
 			body:  "Tacos, Bolognese, Tikka masala + 4 more",
@@ -48,7 +48,7 @@ func TestMessages(t *testing.T) {
 			name:  "plan ready with three dinners",
 			ev:    PlanReady(week, week, []string{"Tacos", "Bolognese", "Tikka masala"}),
 			key:   "plan_ready:2026-10-12",
-			url:   "/plan",
+			url:   "/plan?week=2026-10-12",
 			week:  "2026-10-12",
 			title: "This week's plan is ready",
 			body:  "Tacos, Bolognese, Tikka masala",
@@ -58,7 +58,7 @@ func TestMessages(t *testing.T) {
 			name:  "plan ready for next week",
 			ev:    PlanReady(week, mustDate(t, "2026-10-05"), []string{"Tacos", "Bolognese", "Tikka masala", "Lemon orzo"}),
 			key:   "plan_ready:2026-10-12",
-			url:   "/plan",
+			url:   "/plan?week=2026-10-12",
 			week:  "2026-10-12",
 			title: "Next week's plan is ready",
 			body:  "Tacos, Bolognese, Tikka masala + 1 more",
@@ -68,7 +68,7 @@ func TestMessages(t *testing.T) {
 			name:  "plan ready for a later week",
 			ev:    PlanReady(mustDate(t, "2026-10-26"), mustDate(t, "2026-10-05"), []string{"Tacos"}),
 			key:   "plan_ready:2026-10-26",
-			url:   "/plan",
+			url:   "/plan?week=2026-10-26",
 			week:  "2026-10-26",
 			title: "The plan for the week of Oct 26 is ready",
 			body:  "Tacos",
@@ -78,7 +78,7 @@ func TestMessages(t *testing.T) {
 			name:  "list ready",
 			ev:    ListReady(week, 19, 7),
 			key:   "list_ready:2026-10-12",
-			url:   "/plan/shopping",
+			url:   "/plan/shopping?week=2026-10-12",
 			week:  "2026-10-12",
 			title: "This week's Supply run is ready",
 			body:  "19 items to buy for 7 dinners",
@@ -88,7 +88,7 @@ func TestMessages(t *testing.T) {
 			name:  "list ready singular",
 			ev:    ListReady(week, 1, 1),
 			key:   "list_ready:2026-10-12",
-			url:   "/plan/shopping",
+			url:   "/plan/shopping?week=2026-10-12",
 			week:  "2026-10-12",
 			title: "This week's Supply run is ready",
 			body:  "1 item to buy for 1 dinner",