Fix timeline calendar view and shopping UI bugs (#56, #65-73)

- #56: Add overflow-hidden to card/panel classes to prevent content overflow
- #65: Fix Google Tasks not showing by including tasks without due dates
- #66: Add no-cache headers to prevent stale template responses
- #67: Increase dropdown z-index to 100 for proper layering
- #69: Implement calendar-style Today section with hourly grid (6am-10pm),
       duration-based event heights, and compact overdue/all-day section
- #70: Only reset shopping-mode form on successful submission
- #71: Remove checkboxes from shopping tab (only show in shopping mode)
- #72: Add inline add-item input at end of each store section
- #73: Add Grouped/Flat view toggle for shopping list

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 0e5edcc..bba12ad 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -1230,7 +1230,11 @@ func mealTypeOrder(mealType string) int {
 func (h *Handler) HandleTabShopping(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()
 	stores := h.aggregateShoppingLists(ctx)
-	HTMLResponse(w, h.templates, "shopping-tab", struct{ Stores []models.ShoppingStore }{stores})
+	grouped := r.URL.Query().Get("grouped") != "false" // Default to grouped
+	HTMLResponse(w, h.templates, "shopping-tab", struct {
+		Stores  []models.ShoppingStore
+		Grouped bool
+	}{stores, grouped})
 }
 
 // HandleShoppingQuickAdd adds a user shopping item
@@ -1285,7 +1289,10 @@ func (h *Handler) HandleShoppingQuickAdd(w http.ResponseWriter, r *http.Request)
 	}
 
 	// Return refreshed shopping tab
-	HTMLResponse(w, h.templates, "shopping-tab", struct{ Stores []models.ShoppingStore }{allStores})
+	HTMLResponse(w, h.templates, "shopping-tab", struct {
+		Stores  []models.ShoppingStore
+		Grouped bool
+	}{allStores, true})
 }
 
 // HandleShoppingToggle toggles a shopping item's checked state
@@ -1323,7 +1330,10 @@ func (h *Handler) HandleShoppingToggle(w http.ResponseWriter, r *http.Request) {
 
 	// Return refreshed shopping tab
 	stores := h.aggregateShoppingLists(r.Context())
-	HTMLResponse(w, h.templates, "shopping-tab", struct{ Stores []models.ShoppingStore }{stores})
+	HTMLResponse(w, h.templates, "shopping-tab", struct {
+		Stores  []models.ShoppingStore
+		Grouped bool
+	}{stores, true})
 }
 
 // HandleShoppingMode renders the focused shopping mode for a single store