feat(desktop): preserve mentions across copy and paste

desktop/playwright.config.ts

@@ -78,6 +78,7 @@ export default defineConfig({
         "**/composer-tooltip-dismiss.spec.ts",
         "**/mentions.spec.ts",
         "**/mention-spacing.spec.ts",
+        "**/mention-clipboard.spec.ts",
         "**/cloud-provenance.spec.ts",
         "**/team-mentions.spec.ts",
         "**/persistent-agent-audience.spec.ts",

desktop/src/features/forum/ui/ForumComposer.tsx

@@ -9,10 +9,8 @@ import { useComposerFocusOwnership } from "@/features/messages/lib/useComposerFo
 import { useMediaUpload } from "@/features/messages/lib/useMediaUpload";
 import { isMentionCodeContext } from "@/features/messages/lib/mentionCodeContext";
 import { useMentions } from "@/features/messages/lib/useMentions";
-import {
-  hasMentionClipboardHtml,
-  normalizeMentionClipboardHtml,
-} from "@/features/messages/lib/normalizeMentionClipboard";
+import { hasMentionClipboardHtml } from "@/features/messages/lib/normalizeMentionClipboard";
+import { handleMentionClipboardPaste } from "@/features/messages/lib/mentionClipboardPaste";
 import {
   type LinkSelectionInfo,
   useRichTextEditor,
@@ -121,6 +119,7 @@ export function ForumComposer({
     mentionNames: mentions.knownNames,
     channelNames: channelLinks.knownChannelNames,
     messageLinkChannels: channelLinks.channels,
+    getMentionIdentities: mentions.getMentionIdentities,
     onSubmit: () => submitMessageRef.current(),
     isAutocompleteOpen: isAutocompleteOpenRef,
     onEditLink: (info) => onEditLinkRef.current?.(info),
@@ -242,6 +241,9 @@ export function ForumComposer({
       channelLinks.clearChannels();
       setIsEmojiPickerOpen(false);
       try {
+        // A pasted mention's identity check can still be in flight; extracting
+        // first would publish the label with no `p` tag. Bounded internally.
+        await mentions.settlePendingMentionBindings();
         const pubkeys = await mentions.revalidateMentionPubkeys(
           mentions.extractMentionPubkeys(trimmed),
         );
@@ -292,6 +294,7 @@ export function ForumComposer({
       mentions.cancelMentionAutocomplete,
       mentions.extractMentionPubkeys,
       mentions.revalidateMentionPubkeys,
+      mentions.settlePendingMentionBindings,
       mentions.clearMentions,
       channelLinks.clearChannels,
       richText.clearContent,
@@ -359,6 +362,10 @@ export function ForumComposer({
   // ── Media paste ─────────────────────────────────────────────────────
   const uploadFileRef = React.useRef(media.uploadFile);
   uploadFileRef.current = media.uploadFile;
+  const bindMentionIdentitiesRef = React.useRef(
+    mentions.bindPastedMentionIdentities,
+  );
+  bindMentionIdentitiesRef.current = mentions.bindPastedMentionIdentities;
 
   React.useEffect(() => {
     if (!richText.editor) return;
@@ -379,12 +386,15 @@ export function ForumComposer({
             return true;
           }
 
-          const html = event.clipboardData?.getData("text/html");
-          if (html && hasMentionClipboardHtml(html)) {
-            const cleanHtml = normalizeMentionClipboardHtml(html);
-            event.preventDefault();
-            _view.pasteHTML(cleanHtml);
-            return true;
+          const clipboardData = event.clipboardData;
+          const html = clipboardData?.getData("text/html");
+          if (clipboardData && html && hasMentionClipboardHtml(html)) {
+            return handleMentionClipboardPaste({
+              bindMentionIdentities: bindMentionIdentitiesRef.current,
+              clipboardData,
+              preventDefault: () => event.preventDefault(),
+              view: _view,
+            });
           }
 
           return false;

desktop/src/features/forum/ui/ForumThreadPanel.tsx

@@ -1,6 +1,7 @@
 import { ArrowLeft, MessageSquare } from "lucide-react";
 import * as React from "react";
 
+import { handleTimelineMentionCopy } from "@/features/messages/lib/timelineMentionCopy";
 import {
   resolveUserLabel,
   type UserProfileLookup,
@@ -238,6 +239,7 @@ export function ForumThreadPanel({
       <div
         className="flex-1 overflow-y-auto"
         data-scroll-restoration-id={`forum-thread:${channelId}`}
+        onCopy={handleTimelineMentionCopy}
         ref={scrollRef}
       >
         <div

desktop/src/features/forum/ui/ForumView.tsx

@@ -1,6 +1,7 @@
 import { MessageSquareText } from "lucide-react";
 import * as React from "react";
 
+import { handleTimelineMentionCopy } from "@/features/messages/lib/timelineMentionCopy";
 import { useProfileQuery, useUsersBatchQuery } from "@/features/profile/hooks";
 import { mergeCurrentProfileIntoLookup } from "@/features/profile/lib/identity";
 import { getMentionTagPubkey } from "@/shared/lib/resolveMentionNames";
@@ -207,6 +208,7 @@ export function ForumView({
       <div
         className="flex-1 overflow-y-auto"
         data-scroll-restoration-id={`forum-list:${channel.id}`}
+        onCopy={handleTimelineMentionCopy}
         ref={postsScrollRef}
       >
         {postsQuery.isLoading ? (

desktop/src/features/home/ui/InboxDetailPane.tsx

@@ -42,6 +42,7 @@ import {
   hasRenderedVideoAttachment,
 } from "@/features/messages/lib/videoReviewContext";
 import { getThreadReference } from "@/features/messages/lib/threading";
+import { handleTimelineMentionCopy } from "@/features/messages/lib/timelineMentionCopy";
 import { MessageComposer } from "@/features/messages/ui/MessageComposer";
 import { useAnchoredScroll } from "@/features/messages/ui/useAnchoredScroll";
 import { useComposerHeightPadding } from "@/features/messages/ui/useComposerHeightPadding";
@@ -694,6 +695,11 @@ function InboxMessageDetailPane({
           aria-busy={isThreadContextLoading}
           className="-mt-13 min-h-0 flex-1 overflow-y-auto overscroll-contain pb-32 pt-13 [overflow-anchor:none]"
           data-testid="home-inbox-detail-scroll"
+          // Selection copy across a rendered mention chip: restores the sigil
+          // and the identity sidecar the browser's default copy would drop.
+          // Covers only the messages — the composer is a sibling overlay, so
+          // its own copy handler is untouched.
+          onCopy={handleTimelineMentionCopy}
           onScroll={onScroll}
           ref={scrollContainerRef}
         >
@@ -768,6 +774,7 @@ function InboxMessageDetailPane({
                   onEdit={canEditMessage ? handleSelectEditTarget : undefined}
                   onSelectReplyTarget={handleSelectReplyTarget}
                   onToggleReaction={onToggleReaction}
+                  profiles={profiles}
                   showUnreadBoundary={hasUnreadBoundary}
                   videoReviewCommentRootId={videoReviewPresentation.commentRootIdsByMessageId.get(
                     message.id,

desktop/src/features/home/ui/InboxMessageRow.tsx

@@ -14,6 +14,7 @@ import { MessageReactions } from "@/features/messages/ui/MessageReactions";
 import { UnreadDivider } from "@/features/messages/ui/UnreadDivider";
 import { useReactionHandler } from "@/features/messages/ui/useReactionHandler";
 import { useMessageEmoji } from "@/features/messages/lib/useMessageEmoji";
+import type { UserProfileLookup } from "@/features/profile/lib/identity";
 import { UserProfilePopover } from "@/features/profile/ui/UserProfilePopover";
 import { cn } from "@/shared/lib/cn";
 import { normalizePubkey } from "@/shared/lib/pubkey";
@@ -44,6 +45,8 @@ type InboxMessageRowProps = {
     emoji: string,
     remove: boolean,
   ) => Promise<void>;
+  /** Resolves the mention identities carried by "Copy message". */
+  profiles?: UserProfileLookup;
   showUnreadBoundary?: boolean;
   videoReviewCommentRootId?: string;
   videoReviewContext?: VideoReviewContext;
@@ -61,6 +64,7 @@ export function InboxMessageRow({
   onEdit,
   onSelectReplyTarget,
   onToggleReaction,
+  profiles,
   showUnreadBoundary = false,
   videoReviewCommentRootId,
   videoReviewContext,
@@ -170,6 +174,7 @@ export function InboxMessageRow({
               onReply={
                 canReply ? () => onSelectReplyTarget(message) : undefined
               }
+              profiles={profiles}
               reactionErrorMessage={reactionErrorMessage}
               reactions={reactions}
             />

desktop/src/features/messages/lib/composerMentionCopy.ts

@@ -0,0 +1,52 @@
+import type { EditorView } from "@tiptap/pm/view";
+
+import {
+  buildMentionClipboardHtml,
+  type MentionIdentity,
+} from "./mentionClipboard";
+
+/**
+ * Copy / cut out of the composer.
+ *
+ * A composer mention is plain `@Name ` text decorated from a known-names list;
+ * the pubkey lives outside the document. A default copy therefore moves the
+ * words but not the identity, so moving a draft between channels silently
+ * re-resolves (or drops) who was tagged. Writing the identity sidecar here
+ * keeps the exact pubkey attached to the draft.
+ */
+export function handleComposerMentionCopy({
+  event,
+  identities,
+  isCut,
+  view,
+}: {
+  event: ClipboardEvent;
+  identities: readonly MentionIdentity[];
+  isCut: boolean;
+  view: EditorView;
+}): boolean {
+  const clipboardData = event.clipboardData;
+  if (!clipboardData || view.state.selection.empty) return false;
+
+  const slice = view.state.selection.content();
+  // The same serializer ProseMirror would have used, so the plain flavor is
+  // byte-identical to a default copy (Markdown syntax included).
+  const serializeText = view.someProp("clipboardTextSerializer");
+  const text = serializeText
+    ? serializeText(slice, view)
+    : slice.content.textBetween(0, slice.content.size, "\n\n");
+  if (!text) return false;
+
+  const html = buildMentionClipboardHtml({ identities, text });
+  // No known mention in the selection — leave the copy on its default path
+  // rather than replacing ProseMirror's richer HTML flavor for no gain.
+  if (!html) return false;
+
+  event.preventDefault();
+  clipboardData.setData("text/plain", text);
+  clipboardData.setData("text/html", html);
+  if (isCut) {
+    view.dispatch(view.state.tr.deleteSelection().scrollIntoView());
+  }
+  return true;
+}

desktop/src/features/messages/lib/macEmacsTextShortcuts.ts

@@ -0,0 +1,107 @@
+import { Extension, type KeyboardShortcutCommand } from "@tiptap/core";
+import type { ResolvedPos } from "@tiptap/pm/model";
+import { Selection } from "@tiptap/pm/state";
+
+import { isMacPlatform } from "@/shared/lib/platform";
+
+/**
+ * Bounds of the hard-break-delimited "line" containing `$from`.
+ *
+ * Chat composers use hard breaks for continuation lines, so a ProseMirror
+ * block spans several visual lines. Emacs-style movement has to respect the
+ * visual line, not the block.
+ */
+export function hardBreakLineBounds($from: ResolvedPos) {
+  const parentStart = $from.start();
+  let start = parentStart;
+  let end = parentStart + $from.parent.content.size;
+
+  $from.parent.forEach((node, offset) => {
+    if (node.type.name !== "hardBreak") return;
+    const breakPosition = parentStart + offset;
+    if (breakPosition < $from.pos) {
+      start = breakPosition + node.nodeSize;
+    } else if (breakPosition >= $from.pos && end > breakPosition) {
+      end = breakPosition;
+    }
+  });
+
+  return { end, start };
+}
+
+/**
+ * macOS text fields traditionally support a small set of Emacs-style Control
+ * shortcuts. Keep movement and kill-line scoped to the current
+ * hard-break-delimited line rather than the whole ProseMirror block.
+ */
+export const MacEmacsTextShortcuts = Extension.create({
+  name: "macEmacsTextShortcuts",
+  addKeyboardShortcuts() {
+    const shortcuts: Record<string, KeyboardShortcutCommand> = {};
+    if (!isMacPlatform()) {
+      return shortcuts;
+    }
+
+    return {
+      "Ctrl-a": ({ editor: ed }) => {
+        const { $from } = ed.state.selection;
+        if (!$from.parent.inlineContent) return false;
+        return ed.commands.setTextSelection(hardBreakLineBounds($from).start);
+      },
+      "Ctrl-e": ({ editor: ed }) => {
+        const { $from } = ed.state.selection;
+        if (!$from.parent.inlineContent) return false;
+        return ed.commands.setTextSelection(hardBreakLineBounds($from).end);
+      },
+      "Ctrl-b": ({ editor: ed }) => {
+        const { empty, from } = ed.state.selection;
+        if (!empty || from <= 0) return false;
+        return ed.commands.setTextSelection(from - 1);
+      },
+      "Ctrl-f": ({ editor: ed }) => {
+        const { empty, from } = ed.state.selection;
+        if (!empty || from >= ed.state.doc.content.size) return false;
+        return ed.commands.setTextSelection(from + 1);
+      },
+      "Ctrl-k": ({ editor: ed }) => {
+        const { state, view } = ed;
+        const { $from, empty, from, to } = state.selection;
+
+        if (!empty) {
+          return ed.commands.deleteSelection();
+        }
+
+        if ($from.parent.inlineContent) {
+          const lineEnd = hardBreakLineBounds($from).end;
+          if (from < lineEnd) {
+            return ed.commands.deleteRange({ from, to: lineEnd });
+          }
+
+          const nodeAfter = $from.nodeAfter;
+          if (nodeAfter?.type.name === "hardBreak") {
+            return ed.commands.deleteRange({
+              from,
+              to: from + nodeAfter.nodeSize,
+            });
+          }
+        }
+
+        const blockEnd = $from.end();
+        if (from < blockEnd) {
+          return ed.commands.deleteRange({ from, to: blockEnd });
+        }
+
+        const nextSelection = Selection.findFrom(
+          state.doc.resolve(to),
+          1,
+          true,
+        );
+        if (!nextSelection) return false;
+
+        const transaction = state.tr.delete(to, nextSelection.from);
+        view.dispatch(transaction.scrollIntoView());
+        return true;
+      },
+    };
+  },
+});