Let a multi-selection be copied as plain lines as well as a list

Copying several notes only produced a numbered list, which is wrong for
pasting into a prompt that already has structure. The selection now
offers both forms, Shift+click selects a range, and a selection bar
makes it obvious that more than one note is selected. Esc clears the
selection before it hides the panel.

Sources/Prompt/Store.swift

@@ -269,18 +269,34 @@ final class Store: ObservableObject {
     }
 
     func copyAsList(ids: Set<UUID>) {
-        let items = sections.flatMap(\.items)
-            .filter { ids.contains($0.id) }
-            .sorted { $0.createdAt < $1.createdAt }
-        let texts = items.compactMap { item -> String? in
-            if case .text(let text) = item.content { return text }
-            return nil
-        }
+        let texts = selectedTexts(ids: ids)
         guard !texts.isEmpty else { return }
         let list = texts.enumerated().map { "\($0.offset + 1). \($0.element)" }.joined(separator: "\n")
+        writeToPasteboard(list)
+    }
+
+    /// Same selection as `copyAsList`, but joined with plain newlines so it
+    /// drops into a prompt without numbering.
+    func copyAsLines(ids: Set<UUID>) {
+        let texts = selectedTexts(ids: ids)
+        guard !texts.isEmpty else { return }
+        writeToPasteboard(texts.joined(separator: "\n"))
+    }
+
+    private func selectedTexts(ids: Set<UUID>) -> [String] {
+        sections.flatMap(\.items)
+            .filter { ids.contains($0.id) }
+            .sorted { $0.createdAt < $1.createdAt }
+            .compactMap { item in
+                if case .text(let text) = item.content { return text }
+                return nil
+            }
+    }
+
+    private func writeToPasteboard(_ string: String) {
         let pasteboard = NSPasteboard.general
         pasteboard.clearContents()
-        pasteboard.setString(list, forType: .string)
+        pasteboard.setString(string, forType: .string)
     }
 
     // MARK: - Images