add meal carry over feature

src/views.rs

@@ -1307,7 +1307,10 @@ pub fn list_meals_panel(
             }
         }
         @if editable {
-            button class="button button-small add-meal-button" hx-get=(format!("/meals?picker={}", list_id)) hx-target="#meal-picker" hx-swap="innerHTML" { "+ Add meal" }
+            div class="list-meals-actions" {
+                button class="button button-small add-meal-button" hx-get=(format!("/meals?picker={}", list_id)) hx-target="#meal-picker" hx-swap="innerHTML" { "+ Add meal" }
+                button class="button button-small carry-over-button" hx-get=(format!("/lists/{}/carry", list_id)) hx-target="#meal-picker" hx-swap="innerHTML" { "Carry over" }
+            }
         }
     };
 
@@ -1322,6 +1325,91 @@ pub fn list_meals_panel(
     }
 }
 
+/// The carry-over modal: a picker of active source lists (newest first,
+/// excluding the current list) that the user can import meals from.
+pub fn carry_over_modal(sources: &[GroceryList], dest_list_id: i64) -> Markup {
+    html! {
+        div class="meal-picker-backdrop" onclick="if (event.target === this) this.remove()" {
+            div class="meal-picker-modal" role="dialog" aria-modal="true" aria-label="Carry over meals" {
+                div class="meal-picker-header" {
+                    div {
+                        p class="eyebrow" { "CARRY OVER" }
+                        h2 { "Carry over meals" }
+                    }
+                    button class="meal-picker-close" type="button" aria-label="Close" onclick="this.closest('.meal-picker-backdrop').remove()" { "✕" }
+                }
+                p class="muted carry-intro" { "Import meals from another list. Their ingredients are not re-added — they were already purchased." }
+                @if sources.is_empty() {
+                    div class="meal-picker-empty" {
+                        p { "No other lists to carry from." }
+                    }
+                } @else {
+                    div class="carry-source-picker" {
+                        label for="carry-source" { "From list" }
+                        select
+                            id="carry-source"
+                            name="source"
+                            hx-get=(format!("/lists/{}/carry/meals", dest_list_id))
+                            hx-trigger="change"
+                            hx-target="#carry-results"
+                            hx-swap="innerHTML"
+                        {
+                            option value="" selected disabled { "Choose a list…" }
+                            @for source in sources {
+                                option value=(source.id) { (source.name) }
+                            }
+                        }
+                    }
+                    div id="carry-results" class="carry-results" {}
+                }
+            }
+        }
+    }
+}
+
+/// The selectable meal rows for a chosen source list inside the carry modal.
+pub fn carry_source_meals(
+    list_meals: &[ListMeal],
+    source_id: i64,
+    dest_list_id: i64,
+    csrf_token: &str,
+) -> Markup {
+    html! {
+        @if list_meals.is_empty() {
+            div class="meal-picker-empty" {
+                p { "This list has no meals to carry over." }
+            }
+        } @else {
+            form
+                hx-post=(format!("/lists/{}/carry", dest_list_id))
+                hx-target="#list-items"
+                hx-swap="morph:outerHTML"
+                hx-on::after-request="if (event.detail.successful) this.closest('.meal-picker-backdrop').remove()"
+                class="carry-form"
+            {
+                input type="hidden" name="csrf" value=(csrf_token);
+                input type="hidden" name="source_list_id" value=(source_id);
+                // Collected as a comma-separated list by the checkboxes below;
+                // the form extractor does not coalesce repeated keys into a Vec.
+                input id="carry-selected" type="hidden" name="list_meal_ids" value="";
+                div class="carry-list" {
+                    @for meal in list_meals {
+                        label class="carry-row" {
+                            input
+                                type="checkbox"
+                                value=(meal.id)
+                                onchange="var form=this.closest('form'); var box=form.querySelector('#carry-selected'); box.value=Array.from(form.querySelectorAll('input[type=checkbox]:checked')).map(function(c){return c.value}).join(',');";
+                            span class="carry-row-icon" { "🍽" }
+                            span class="carry-row-name" { (meal.name) }
+                        }
+                    }
+                }
+                button class="button button-primary carry-submit" type="submit" { "Carry over" }
+            }
+        }
+    }
+}
+
 pub fn presence_panel(presence: &[PresenceUser], out_of_band: bool) -> Markup {
     if out_of_band {
         html! {