Make the row checkbox select items instead of ticking them off

The checkbox was marking items done, but the intent was to gather items
and act on them: tick several, then right-click to copy, copy as a list,
move, merge or delete them all at once. Done is still available from the
same menu, it is just no longer what the checkbox does.

Sources/Prompt/Store.swift

@@ -190,18 +190,49 @@ final class Store: ObservableObject {
     }
 
     func delete(_ id: UUID) {
+        delete(ids: [id])
+    }
+
+    /// Deletes every item in `ids` in one pass, cleaning up their image files.
+    func delete(ids: Set<UUID>) {
+        guard !ids.isEmpty else { return }
+        var removedAny = false
         for sectionIndex in sections.indices {
-            if let itemIndex = sections[sectionIndex].items.firstIndex(where: { $0.id == id }) {
-                let item = sections[sectionIndex].items[itemIndex]
+            for item in sections[sectionIndex].items where ids.contains(item.id) {
+                removedAny = true
                 if case .image(let filename) = item.content {
                     try? FileManager.default.removeItem(at: imagesDirectory.appendingPathComponent(filename))
                     imageCache.removeObject(forKey: filename as NSString)
                 }
-                sections[sectionIndex].items.remove(at: itemIndex)
-                save()
-                return
+            }
+            sections[sectionIndex].items.removeAll { ids.contains($0.id) }
+        }
+        if removedAny { save() }
+    }
+
+    func setDone(_ done: Bool, ids: Set<UUID>) {
+        guard !ids.isEmpty else { return }
+        for sectionIndex in sections.indices {
+            for itemIndex in sections[sectionIndex].items.indices
+            where ids.contains(sections[sectionIndex].items[itemIndex].id) {
+                sections[sectionIndex].items[itemIndex].done = done
             }
         }
+        save()
+    }
+
+    /// Moves every item in `ids` into `targetSectionID`, keeping their order.
+    func move(ids: Set<UUID>, to targetSectionID: UUID) {
+        guard !ids.isEmpty,
+              let targetIndex = sections.firstIndex(where: { $0.id == targetSectionID }) else { return }
+        var moved: [PromptItem] = []
+        for sectionIndex in sections.indices where sectionIndex != targetIndex {
+            moved.append(contentsOf: sections[sectionIndex].items.filter { ids.contains($0.id) })
+            sections[sectionIndex].items.removeAll { ids.contains($0.id) }
+        }
+        guard !moved.isEmpty else { return }
+        sections[targetIndex].items.append(contentsOf: moved)
+        save()
     }
 
     func move(_ id: UUID, to targetSectionID: UUID) {