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/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",