Task #410: floating draggable note popup + reply alert at sender

Convert the incoming-note popup from a centered AlertDialog modal into
a floating, draggable, animated card (no backdrop) and surface the
same card variant at the original sender when the recipient replies.

UI / popup:
- Rewrite IncomingNotePopup as a fixed-positioned card with custom
  pointer-event drag handler, viewport clamping, sessionStorage-
  persisted position keyed per user, RTL-aware default anchor, ESC
  dismissal, scale-in/fade enter animation, and click-through layer
  (pointer-events-none wrapper). Initial framer-motion impl crashed
  in vite (useRef-of-null / Invalid hook call); rewrote without
  framer-motion using plain CSS transitions for stability.
- isDragging tracked in state so the transform transition is reliably
  disabled during drag (per architect review).

Reply variant:
- Generalize incoming-note-queue with PopupPayload discriminated union
  (note | reply); reply dedupe by replyId, note dedupe by noteId;
  applyDismiss accepts number | {replyId}.
- Floating card switches heading + actions for reply variant: shows
  replier name, reply text, and openThread / replyBack actions; the
  recipient-only mark-read action is suppressed (owner can't mark own
  outbound note read).

Sound + socket:
- New note_replied client handler enqueues the reply payload and plays
  notificationSoundNote + vibrationEnabledNote (gated by
  notificationsMuted + notifyNotesEnabled — no new prefs), deduped
  via playedReplyIdsRef.
- Server emit at /notes/:id/reply enriched with replyContent (≤280
  chars), replier (UserSummary), noteTitle, color so the client can
  render without an extra round-trip.

i18n + tests:
- Add en/ar keys: replyHeading, replyHeadingNoSender, replyBack,
  openThread, dragHint.
- Extend notes-popup-on-receive.spec.mjs: first test asserts
  no [role=alertdialog], drag-handle visible, data-popup-kind="note";
  new reply test asserts data-popup-kind="reply", reply text +
  replier name visible, mark-read action absent, chime fires once
  for sender on reply.

Drift from plan:
- Used custom pointer-event drag instead of framer-motion drag — the
  framer-motion impl crashed in vite (React-instance null in dev).
  Same UX (drag from header only, click-through behind card).
- E2E: api-server unit test failures (executive-meetings, pre-existing
  and unrelated) abort the test workflow before playwright runs;
  could not get a clean green run during this session. Tx-os
  typecheck passes; browser console clean; popup interface (testIds,
  data attrs, text) is identical to the previously-working
  framer-motion run, so no functional regression expected.

artifacts/api-server/src/routes/notes.ts

@@ -754,10 +754,18 @@ router.post("/notes/:id/reply", requireAuth, async (req, res): Promise<void> =>
     })
     .returning();
   await emitToUser(otherPartyUserId, "notification_created", { ...notif, type: "note" });
+  // Enrich the realtime payload so the recipient's client can render the
+  // floating reply card without an extra round-trip. We truncate the body
+  // to keep the socket frame small; the full reply is still in /notes.
+  const replyContentSnippet = (reply.content ?? "").slice(0, 280);
   await emitToUser(otherPartyUserId, "note_replied", {
     noteId: id.id,
     recipientUserId: isOwner ? otherPartyUserId : userId,
     replyId: reply.id,
+    replyContent: replyContentSnippet,
+    replier: replier ?? null,
+    noteTitle: liveNote?.title ?? null,
+    color: liveNote?.color ?? "default",
   });
 
   res.status(201).json({

artifacts/tx-os/src/components/notes/incoming-note-popup.tsx

@@ -1,14 +1,14 @@
+import {
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  type PointerEvent as ReactPointerEvent,
+} from "react";
 import { useTranslation } from "react-i18next";
 import { useLocation } from "wouter";
-import { Reply, Check, ExternalLink, X } from "lucide-react";
-import {
-  AlertDialog,
-  AlertDialogContent,
-  AlertDialogHeader,
-  AlertDialogTitle,
-  AlertDialogDescription,
-  AlertDialogFooter,
-} from "@/components/ui/alert-dialog";
+import { Reply, Check, ExternalLink, X, GripVertical } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import {
   colorBg,
@@ -16,47 +16,216 @@ import {
   userDisplayName,
   type UserSummary,
 } from "@/lib/notes-api";
-import { useIncomingNotePopup } from "@/contexts/IncomingNotePopupContext";
+import {
+  useIncomingNotePopup,
+  type PopupPayload,
+} from "@/contexts/IncomingNotePopupContext";
+import { useAuth } from "@/contexts/AuthContext";
 
 function avatarInitial(u: UserSummary | null, lang: string): string {
   const name = userDisplayName(u, lang);
   return name.trim().charAt(0).toUpperCase() || "?";
 }
 
+interface StoredPos {
+  x: number;
+  y: number;
+}
+
+const CARD_WIDTH = 384;
+const CARD_HEIGHT_ESTIMATE = 280;
+const VIEWPORT_MARGIN = 8;
+const TOP_INSET = 80;
+const SIDE_INSET = 24;
+
+function storageKey(userId: number | null | undefined): string {
+  return `txos:floating-note-popup:pos:${userId ?? "anon"}`;
+}
+
+function loadStoredPos(userId: number | null | undefined): StoredPos | null {
+  if (typeof window === "undefined") return null;
+  try {
+    const raw = window.sessionStorage.getItem(storageKey(userId));
+    if (!raw) return null;
+    const parsed = JSON.parse(raw) as Partial<StoredPos>;
+    if (typeof parsed.x !== "number" || typeof parsed.y !== "number") return null;
+    return { x: parsed.x, y: parsed.y };
+  } catch {
+    return null;
+  }
+}
+
+function saveStoredPos(
+  userId: number | null | undefined,
+  pos: StoredPos,
+): void {
+  if (typeof window === "undefined") return;
+  try {
+    window.sessionStorage.setItem(storageKey(userId), JSON.stringify(pos));
+  } catch {
+    /* ignore quota / disabled storage */
+  }
+}
+
+/**
+ * Default anchor when the user hasn't dragged the card yet.
+ * RTL → top-left edge of the viewport; LTR → top-right edge. Keeps
+ * the card clear of typical header bars (top inset of 80px).
+ */
+function defaultAnchor(isRtl: boolean): StoredPos {
+  if (typeof window === "undefined") return { x: SIDE_INSET, y: TOP_INSET };
+  const x = isRtl
+    ? SIDE_INSET
+    : Math.max(SIDE_INSET, window.innerWidth - CARD_WIDTH - SIDE_INSET);
+  return { x, y: TOP_INSET };
+}
+
+function clampToViewport(pos: StoredPos): StoredPos {
+  if (typeof window === "undefined") return pos;
+  const maxX = Math.max(
+    VIEWPORT_MARGIN,
+    window.innerWidth - CARD_WIDTH - VIEWPORT_MARGIN,
+  );
+  const maxY = Math.max(
+    VIEWPORT_MARGIN,
+    window.innerHeight - CARD_HEIGHT_ESTIMATE - VIEWPORT_MARGIN,
+  );
+  return {
+    x: Math.min(Math.max(VIEWPORT_MARGIN, pos.x), maxX),
+    y: Math.min(Math.max(VIEWPORT_MARGIN, pos.y), maxY),
+  };
+}
+
 export function IncomingNotePopup() {
   const { t, i18n } = useTranslation();
   const isRtl = i18n.language === "ar";
   const [, setLocation] = useLocation();
   const { current, queueLength, dismiss } = useIncomingNotePopup();
   const markRead = useMarkNoteRead();
+  const { user } = useAuth();
+  const userId = user?.id ?? null;
+
+  const [position, setPosition] = useState<StoredPos>(() =>
+    clampToViewport(loadStoredPos(userId) ?? defaultAnchor(isRtl)),
+  );
+  const [enterAnim, setEnterAnim] = useState(false);
+  // Reactive flag mirrored from `dragRef`. The ref drives per-pixel
+  // pointermove updates without re-rendering, but we still need a
+  // reactive bit so React turns OFF the transform transition during
+  // a drag — otherwise pointermove writes race the CSS transition
+  // and the card stutters.
+  const [isDragging, setIsDragging] = useState(false);
+
+  // Pointer-event drag state. Kept in a ref so dragging doesn't churn
+  // through React renders on every pointermove — only the inline style
+  // is mutated until pointerup, when we commit the final position.
+  const dragRef = useRef<{
+    pointerId: number;
+    startClientX: number;
+    startClientY: number;
+    startPosX: number;
+    startPosY: number;
+  } | null>(null);
+  const cardRef = useRef<HTMLDivElement | null>(null);
+
+  // Re-anchor when identity / language direction changes so the previous
+  // user's stored position doesn't leak into a new session and the
+  // default corner flips correctly on LTR↔RTL switch.
+  useEffect(() => {
+    setPosition(clampToViewport(loadStoredPos(userId) ?? defaultAnchor(isRtl)));
+    // Intentional: only re-anchor on identity / direction change.
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [userId, isRtl]);
+
+  // Trigger the "scale-in + fade" enter animation on mount of each new
+  // popup entry. We toggle from `false → true` on the next paint so the
+  // CSS transition has a starting state to interpolate from.
+  useEffect(() => {
+    if (!current) return;
+    setEnterAnim(false);
+    const id = requestAnimationFrame(() => setEnterAnim(true));
+    return () => cancelAnimationFrame(id);
+  }, [current]);
+
+  // Keep the card on-screen if the viewport shrinks (rotate / resize).
+  useEffect(() => {
+    if (typeof window === "undefined") return;
+    const onResize = () => setPosition((p) => clampToViewport(p));
+    window.addEventListener("resize", onResize);
+    return () => window.removeEventListener("resize", onResize);
+  }, []);
+
+  const handleDismissCurrent = useCallback(() => {
+    if (!current) return;
+    if (current.kind === "reply") {
+      dismiss({ replyId: current.replyId });
+    } else {
+      dismiss(current.noteId);
+    }
+  }, [current, dismiss]);
+
+  // ESC dismisses the current entry (parity with the old modal).
+  useEffect(() => {
+    if (!current) return;
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === "Escape") {
+        e.preventDefault();
+        handleDismissCurrent();
+      }
+    };
+    window.addEventListener("keydown", onKey);
+    return () => window.removeEventListener("keydown", onKey);
+  }, [current, handleDismissCurrent]);
+
+  const isReply = current?.kind === "reply";
+  const replyPayload = isReply
+    ? (current as Extract<PopupPayload, { kind: "reply" }>)
+    : null;
+
+  const senderForHeader: UserSummary | null = useMemo(() => {
+    if (!current) return null;
+    if (replyPayload) return replyPayload.replier;
+    return current.sender;
+  }, [current, replyPayload]);
+
+  const senderName = senderForHeader
+    ? userDisplayName(senderForHeader, i18n.language)
+    : null;
+
+  const heading = useMemo(() => {
+    if (!current) return "";
+    if (replyPayload) {
+      return senderName
+        ? t("notes.popup.replyHeading", { name: senderName })
+        : t("notes.popup.replyHeadingNoSender");
+    }
+    return senderName
+      ? t("notes.popup.heading", { name: senderName })
+      : t("notes.popup.headingNoSender");
+  }, [current, replyPayload, senderName, t]);
 
   if (!current) return null;
 
-  const senderName = current.sender
-    ? userDisplayName(current.sender, i18n.language)
-    : null;
-  const heading = senderName
-    ? t("notes.popup.heading", { name: senderName })
-    : t("notes.popup.headingNoSender");
-
   const acknowledge = () => {
-    markRead.mutate(current.noteId);
+    // Only the recipient (note variant) marks-as-read. The reply
+    // variant goes to the *original sender* (note owner), who can't
+    // mark their own outbound note read.
+    if (!replyPayload) {
+      markRead.mutate(current.noteId);
+    }
   };
 
-  const handleDismiss = () => dismiss(current.noteId);
-
+  const handleDismiss = () => handleDismissCurrent();
   const handleMarkRead = () => {
     acknowledge();
     handleDismiss();
   };
-
   const handleReply = () => {
     acknowledge();
     const noteId = current.noteId;
     handleDismiss();
     setLocation(`/notes?thread=${noteId}&reply=1`);
   };
-
   const handleOpen = () => {
     acknowledge();
     const noteId = current.noteId;
@@ -64,107 +233,217 @@ export function IncomingNotePopup() {
     setLocation(`/notes?thread=${noteId}`);
   };
 
+  // ---- Drag handlers ----
+  // Only the header (`.drag-handle`) starts a drag. The card itself
+  // is positioned `fixed` and updated via inline style during move; on
+  // pointerup the final position is committed to React state +
+  // sessionStorage. Buttons inside the body get their own clicks
+  // because we never call preventDefault on them.
+  const onHandlePointerDown = (e: ReactPointerEvent<HTMLDivElement>) => {
+    if (e.button !== 0 && e.pointerType === "mouse") return;
+    const target = e.currentTarget;
+    target.setPointerCapture(e.pointerId);
+    dragRef.current = {
+      pointerId: e.pointerId,
+      startClientX: e.clientX,
+      startClientY: e.clientY,
+      startPosX: position.x,
+      startPosY: position.y,
+    };
+    setIsDragging(true);
+  };
+
+  const onHandlePointerMove = (e: ReactPointerEvent<HTMLDivElement>) => {
+    const drag = dragRef.current;
+    if (!drag || drag.pointerId !== e.pointerId) return;
+    const next = clampToViewport({
+      x: drag.startPosX + (e.clientX - drag.startClientX),
+      y: drag.startPosY + (e.clientY - drag.startClientY),
+    });
+    if (cardRef.current) {
+      cardRef.current.style.transform = `translate3d(${next.x}px, ${next.y}px, 0)`;
+    }
+  };
+
+  const onHandlePointerEnd = (e: ReactPointerEvent<HTMLDivElement>) => {
+    const drag = dragRef.current;
+    if (!drag || drag.pointerId !== e.pointerId) return;
+    const target = e.currentTarget;
+    if (target.hasPointerCapture(e.pointerId)) {
+      target.releasePointerCapture(e.pointerId);
+    }
+    const next = clampToViewport({
+      x: drag.startPosX + (e.clientX - drag.startClientX),
+      y: drag.startPosY + (e.clientY - drag.startClientY),
+    });
+    dragRef.current = null;
+    setIsDragging(false);
+    setPosition(next);
+    saveStoredPos(userId, next);
+  };
+
+  const bodyTitle = replyPayload
+    ? replyPayload.noteTitle?.trim() || t("notes.popup.untitled")
+    : current.title?.trim() || t("notes.popup.untitled");
+  const bodyContent = replyPayload
+    ? replyPayload.replyContent
+    : current.content;
+
   return (
-    <AlertDialog open={true}>
-      <AlertDialogContent
-        dir={isRtl ? "rtl" : "ltr"}
+    // Full-viewport invisible layer. `pointer-events-none` so clicks
+    // fall through to the app — the popup is "floating", not modal.
+    <div
+      className="fixed inset-0 z-[110] pointer-events-none"
+      aria-hidden="false"
+    >
+      <div
+        ref={cardRef}
+        key={replyPayload ? `reply-${replyPayload.replyId}` : `note-${current.noteId}`}
+        role="dialog"
+        aria-label={heading}
         data-testid="incoming-note-popup"
-        className="max-w-md z-[110] ring-4 ring-amber-400/70 shadow-2xl shadow-amber-500/30 animate-in zoom-in-95 fade-in-0 duration-200"
+        data-popup-kind={replyPayload ? "reply" : "note"}
+        dir={isRtl ? "rtl" : "ltr"}
+        className="pointer-events-auto absolute top-0 left-0"
+        style={{
+          width: CARD_WIDTH,
+          maxWidth: "calc(100vw - 16px)",
+          transform: `translate3d(${position.x}px, ${position.y}px, 0)`,
+          transition: isDragging
+            ? "none"
+            : "transform 220ms cubic-bezier(0.34, 1.56, 0.64, 1), opacity 200ms ease-out",
+          opacity: enterAnim ? 1 : 0,
+          willChange: "transform",
+        }}
       >
-        <AlertDialogHeader>
-          <AlertDialogTitle className="flex items-center gap-3">
+        <div
+          className={`rounded-2xl bg-background ring-4 ring-amber-400/70 shadow-2xl shadow-amber-500/30 overflow-hidden transition-transform duration-200 ${
+            enterAnim ? "scale-100" : "scale-95"
+          }`}
+        >
+          {/* Drag handle / header */}
+          <div
+            onPointerDown={onHandlePointerDown}
+            onPointerMove={onHandlePointerMove}
+            onPointerUp={onHandlePointerEnd}
+            onPointerCancel={onHandlePointerEnd}
+            className="flex items-center gap-3 px-4 py-3 cursor-grab active:cursor-grabbing select-none border-b bg-muted/40 touch-none"
+            data-testid="incoming-note-popup-drag-handle"
+            title={t("notes.popup.dragHint")}
+          >
+            <GripVertical
+              size={16}
+              className="text-muted-foreground shrink-0"
+              aria-hidden="true"
+            />
             <span className="relative shrink-0">
               <span
                 className="absolute inset-0 rounded-full bg-amber-400/60 animate-ping"
                 aria-hidden="true"
               />
-              {current.sender?.avatarUrl ? (
+              {senderForHeader?.avatarUrl ? (
                 <img
-                  src={current.sender.avatarUrl}
+                  src={senderForHeader.avatarUrl}
                   alt=""
-                  className="relative h-9 w-9 rounded-full object-cover ring-2 ring-amber-400"
+                  className="relative h-8 w-8 rounded-full object-cover ring-2 ring-amber-400"
                 />
               ) : (
-                <div className="relative h-9 w-9 rounded-full bg-amber-200 text-amber-900 font-semibold flex items-center justify-center ring-2 ring-amber-400">
-                  {avatarInitial(current.sender, i18n.language)}
+                <div className="relative h-8 w-8 rounded-full bg-amber-200 text-amber-900 text-sm font-semibold flex items-center justify-center ring-2 ring-amber-400">
+                  {avatarInitial(senderForHeader, i18n.language)}
                 </div>
               )}
             </span>
-            <span className="text-base">{heading}</span>
-          </AlertDialogTitle>
-          <AlertDialogDescription className="sr-only">
-            {heading}
-          </AlertDialogDescription>
-        </AlertDialogHeader>
-
-        <div
-          className={`rounded-xl border border-black/5 shadow-sm p-4 ${colorBg(
-            current.color,
-          )}`}
-          data-testid="incoming-note-popup-body"
-        >
-          <div className="font-semibold text-sm text-foreground break-words">
-            {current.title?.trim() || t("notes.popup.untitled")}
-          </div>
-          {current.content && (
-            <div className="text-sm text-foreground/80 mt-2 whitespace-pre-wrap break-words max-h-[40vh] overflow-y-auto">
-              {current.content}
+            <div className="flex-1 min-w-0">
+              <div className="text-sm font-semibold truncate">{heading}</div>
             </div>
-          )}
-        </div>
-
-        {queueLength > 1 && (
-          <div
-            className="text-xs text-muted-foreground"
-            data-testid="incoming-note-popup-queue"
-          >
-            {t("notes.popup.queueMore", { count: queueLength - 1 })}
+            <button
+              type="button"
+              onClick={handleDismiss}
+              onPointerDown={(e) => e.stopPropagation()}
+              className="text-muted-foreground hover:text-foreground rounded-md p-1"
+              aria-label={t("notes.popup.dismiss")}
+              data-testid="incoming-note-popup-close"
+            >
+              <X size={16} />
+            </button>
           </div>
-        )}
 
-        <AlertDialogFooter className="flex flex-wrap gap-2 sm:flex-nowrap">
-          <Button
-            type="button"
-            variant="ghost"
-            size="sm"
-            onClick={handleDismiss}
-            data-testid="incoming-note-popup-dismiss"
-          >
-            <X size={14} className="me-1" />
-            {t("notes.popup.dismiss")}
-          </Button>
-          <Button
-            type="button"
-            variant="outline"
-            size="sm"
-            onClick={handleOpen}
-            data-testid="incoming-note-popup-open"
-          >
-            <ExternalLink size={14} className="me-1" />
-            {t("notes.popup.openInNotes")}
-          </Button>
-          <Button
-            type="button"
-            variant="outline"
-            size="sm"
-            onClick={handleMarkRead}
-            data-testid="incoming-note-popup-mark-read"
-          >
-            <Check size={14} className="me-1" />
-            {t("notes.popup.markRead")}
-          </Button>
-          <Button
-            type="button"
-            size="sm"
-            autoFocus
-            onClick={handleReply}
-            data-testid="incoming-note-popup-reply"
-          >
-            <Reply size={14} className="me-1" />
-            {t("notes.popup.reply")}
-          </Button>
-        </AlertDialogFooter>
-      </AlertDialogContent>
-    </AlertDialog>
+          {/* Body */}
+          <div className="p-4 space-y-3">
+            <div
+              className={`rounded-xl border border-black/5 shadow-sm p-3 ${colorBg(
+                current.color,
+              )}`}
+              data-testid="incoming-note-popup-body"
+            >
+              <div className="font-semibold text-sm text-foreground break-words">
+                {bodyTitle}
+              </div>
+              {bodyContent && (
+                <div className="text-sm text-foreground/80 mt-2 whitespace-pre-wrap break-words max-h-[40vh] overflow-y-auto">
+                  {bodyContent}
+                </div>
+              )}
+            </div>
+
+            {queueLength > 1 && (
+              <div
+                className="text-xs text-muted-foreground"
+                data-testid="incoming-note-popup-queue"
+              >
+                {t("notes.popup.queueMore", { count: queueLength - 1 })}
+              </div>
+            )}
+
+            <div className="flex flex-wrap gap-2 sm:flex-nowrap justify-end">
+              <Button
+                type="button"
+                variant="ghost"
+                size="sm"
+                onClick={handleDismiss}
+                data-testid="incoming-note-popup-dismiss"
+              >
+                <X size={14} className="me-1" />
+                {t("notes.popup.dismiss")}
+              </Button>
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                onClick={handleOpen}
+                data-testid="incoming-note-popup-open"
+              >
+                <ExternalLink size={14} className="me-1" />
+                {replyPayload
+                  ? t("notes.popup.openThread")
+                  : t("notes.popup.openInNotes")}
+              </Button>
+              {!replyPayload && (
+                <Button
+                  type="button"
+                  variant="outline"
+                  size="sm"
+                  onClick={handleMarkRead}
+                  data-testid="incoming-note-popup-mark-read"
+                >
+                  <Check size={14} className="me-1" />
+                  {t("notes.popup.markRead")}
+                </Button>
+              )}
+              <Button
+                type="button"
+                size="sm"
+                autoFocus
+                onClick={handleReply}
+                data-testid="incoming-note-popup-reply"
+              >
+                <Reply size={14} className="me-1" />
+                {replyPayload ? t("notes.popup.replyBack") : t("notes.popup.reply")}
+              </Button>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
   );
 }

artifacts/tx-os/src/contexts/IncomingNotePopupContext.tsx

@@ -13,26 +13,30 @@ import {
   applyDismiss,
   applyEnqueue,
   shouldEnqueueNote,
-  type IncomingNotePayload,
+  type PopupPayload,
 } from "@/lib/incoming-note-queue";
 
-export type { IncomingNotePayload } from "@/lib/incoming-note-queue";
+export type {
+  PopupPayload,
+  IncomingNotePayload,
+  IncomingReplyPayload,
+} from "@/lib/incoming-note-queue";
 
 interface IncomingNotePopupContextValue {
-  current: IncomingNotePayload | null;
+  current: PopupPayload | null;
   queueLength: number;
   /**
    * Adds the payload to the FIFO popup queue. Returns true if the
    * payload was actually queued, false if it was suppressed (sender's
-   * own note, duplicate noteId, or malformed). Callers use the boolean
-   * to gate side-effects like the chime so we don't beep for our own
-   * outgoing notes or for replayed socket events.
+   * own note/reply, duplicate id, or malformed). Callers use the
+   * boolean to gate side-effects like the chime so we don't beep for
+   * our own outgoing actions or for replayed socket events.
    */
   enqueue: (
-    payload: IncomingNotePayload,
+    payload: PopupPayload,
     currentUserId: number | null,
   ) => boolean;
-  dismiss: (noteId: number) => void;
+  dismiss: (target: number | { replyId: number }) => void;
   clear: () => void;
 }
 
@@ -40,7 +44,7 @@ const IncomingNotePopupContext =
   createContext<IncomingNotePopupContextValue | null>(null);
 
 export function IncomingNotePopupProvider({ children }: { children: ReactNode }) {
-  const [queue, setQueue] = useState<IncomingNotePayload[]>([]);
+  const [queue, setQueue] = useState<PopupPayload[]>([]);
   const { user } = useAuth();
 
   // Drop any queued popups whenever the active user identity changes
@@ -53,16 +57,13 @@ export function IncomingNotePopupProvider({ children }: { children: ReactNode })
 
   // Track the latest queue in a ref so `enqueue` can decide acceptance
   // synchronously without depending on React's state-updater timing.
-  const queueRef = useRef<IncomingNotePayload[]>(queue);
+  const queueRef = useRef<PopupPayload[]>(queue);
   useEffect(() => {
     queueRef.current = queue;
   }, [queue]);
 
   const enqueue = useCallback(
-    (payload: IncomingNotePayload, currentUserId: number | null): boolean => {
-      // Use the pure predicate to decide acceptance against the current
-      // queue snapshot, then commit via setQueue. Both sides share the
-      // same suppression rules in `incoming-note-queue.ts`.
+    (payload: PopupPayload, currentUserId: number | null): boolean => {
       const accepted = shouldEnqueueNote(
         queueRef.current,
         payload,
@@ -76,8 +77,8 @@ export function IncomingNotePopupProvider({ children }: { children: ReactNode })
     [],
   );
 
-  const dismiss = useCallback((noteId: number) => {
-    setQueue((prev) => applyDismiss(prev, noteId));
+  const dismiss = useCallback((target: number | { replyId: number }) => {
+    setQueue((prev) => applyDismiss(prev, target));
   }, []);
 
   const clear = useCallback(() => setQueue([]), []);

artifacts/tx-os/src/hooks/use-notifications-socket.ts

@@ -21,6 +21,7 @@ import i18n from "@/i18n";
 import {
   useIncomingNotePopup,
   type IncomingNotePayload,
+  type IncomingReplyPayload,
 } from "@/contexts/IncomingNotePopupContext";
 
 const BASE = import.meta.env.BASE_URL.replace(/\/$/, "");
@@ -43,6 +44,9 @@ export function useNotificationsSocket() {
   // doesn't beep twice for the same incoming note. Mirrors the
   // `playedRef` pattern used by upcoming-meeting-alert.
   const playedNoteIdsRef = useRef<Set<number>>(new Set());
+  // Same dedupe shape as `playedNoteIdsRef`, but keyed on replyId so a
+  // reconnect that replays a `note_replied` event doesn't re-chime.
+  const playedReplyIdsRef = useRef<Set<number>>(new Set());
 
   useEffect(() => {
     if (!user) return;
@@ -170,14 +174,83 @@ export function useNotificationsSocket() {
       });
     });
 
-    socket.on("note_replied", () => {
-      queryClient.invalidateQueries({ queryKey: ["notes"] });
-      if (nowMs() - connectedAtRef.current < SOCKET_WARMUP_MS) return;
-      toast({
-        title: i18n.t("notes.toast.replied.title"),
-        description: i18n.t("notes.toast.replied.desc"),
-      });
-    });
+    socket.on(
+      "note_replied",
+      (payload?: Partial<IncomingReplyPayload> & { recipientUserId?: number }) => {
+        queryClient.invalidateQueries({ queryKey: ["notes"] });
+        const inWarmup = nowMs() - connectedAtRef.current < SOCKET_WARMUP_MS;
+        let enqueued = false;
+        // The server emits `note_replied` only to the *original note
+        // owner* (i.e. the sender). Build a reply popup payload — the
+        // queue dedupes on replyId so a socket reconnect that replays
+        // the same event won't re-show or re-chime.
+        if (
+          payload &&
+          typeof payload.noteId === "number" &&
+          typeof payload.replyId === "number"
+        ) {
+          // The "sender" of the *original* note is the current user
+          // (the owner) — we don't have their full UserSummary on the
+          // payload, but the floating card never renders it for the
+          // reply variant; it shows the replier instead. Use the
+          // replier's id as a stand-in for senderUserId so the
+          // queue's "ignore my own outgoing" guard treats this event
+          // as inbound (the replier is *not* the current user).
+          const replierId = payload.replier?.id;
+          const senderUserId =
+            typeof replierId === "number" ? replierId : -1;
+          const full: IncomingReplyPayload = {
+            kind: "reply",
+            noteId: payload.noteId,
+            replyId: payload.replyId,
+            replyContent:
+              typeof payload.replyContent === "string"
+                ? payload.replyContent
+                : "",
+            replier: payload.replier ?? null,
+            noteTitle:
+              typeof payload.noteTitle === "string" ? payload.noteTitle : "",
+            title:
+              typeof payload.noteTitle === "string" ? payload.noteTitle : "",
+            content:
+              typeof payload.replyContent === "string"
+                ? payload.replyContent
+                : "",
+            color:
+              typeof payload.color === "string" ? payload.color : "default",
+            senderUserId,
+            sender: payload.replier ?? null,
+          };
+          enqueued = enqueueNotePopupRef.current(
+            full,
+            currentUserIdRef.current,
+          );
+        }
+        if (inWarmup) return;
+        // Sound + vibration mirror the new-note alert. Reuse the same
+        // notes channel prefs (notificationSoundNote /
+        // vibrationEnabledNote / notifyNotesEnabled) — the user
+        // confirmed they want a single sensory profile for both
+        // events. Dedupe by replyId via a per-session set.
+        const replyId = payload?.replyId;
+        if (
+          enqueued &&
+          typeof replyId === "number" &&
+          !user.notificationsMuted &&
+          user.notifyNotesEnabled &&
+          !playedReplyIdsRef.current.has(replyId)
+        ) {
+          playedReplyIdsRef.current.add(replyId);
+          notificationPlayer.play(user.notificationSoundNote, {
+            vibrate: user.vibrationEnabledNote,
+          });
+        }
+        toast({
+          title: i18n.t("notes.toast.replied.title"),
+          description: i18n.t("notes.toast.replied.desc"),
+        });
+      },
+    );
 
     socket.on("note_status_changed", () => {
       queryClient.invalidateQueries({ queryKey: ["notes"] });

artifacts/tx-os/src/lib/incoming-note-queue.ts

@@ -1,6 +1,14 @@
 import type { UserSummary } from "@/lib/notes-api";
 
-export interface IncomingNotePayload {
+/**
+ * Common fields shared by every floating-card popup entry, regardless
+ * of whether it represents a fresh incoming note or a reply on an
+ * existing thread. The popup component switches on `kind` to render the
+ * matching variant; the queue uses `noteId` for primary dedupe and
+ * (for replies) `replyId` as a secondary dedupe key so a reconnect
+ * storm can't replay the same reply card twice.
+ */
+interface BasePayload {
   noteId: number;
   recipientRowId?: number;
   title: string;
@@ -11,20 +19,48 @@ export interface IncomingNotePayload {
   sender: UserSummary | null;
 }
 
+export interface IncomingNotePayload extends BasePayload {
+  kind?: "note";
+}
+
+export interface IncomingReplyPayload extends BasePayload {
+  kind: "reply";
+  replyId: number;
+  replyContent: string;
+  replier: UserSummary | null;
+  noteTitle: string;
+}
+
+export type PopupPayload = IncomingNotePayload | IncomingReplyPayload;
+
+function isReply(p: PopupPayload): p is IncomingReplyPayload {
+  return p.kind === "reply";
+}
+
+function payloadKey(p: PopupPayload): string {
+  return isReply(p) ? `reply:${p.replyId}` : `note:${p.noteId}`;
+}
+
 /**
  * Pure FIFO + dedupe + sender-suppression for the incoming-note queue.
  * Exported so unit tests can exercise the rules without React.
+ *
+ * Reply entries are deduped by `replyId`; note entries by `noteId`.
+ * A reply on the *same* underlying note as a queued note is allowed —
+ * the user wants to see both events.
  */
 export function applyEnqueue(
-  queue: IncomingNotePayload[],
-  payload: IncomingNotePayload,
+  queue: PopupPayload[],
+  payload: PopupPayload,
   currentUserId: number | null,
-): IncomingNotePayload[] {
+): PopupPayload[] {
   if (!payload || typeof payload.noteId !== "number") return queue;
   if (currentUserId != null && payload.senderUserId === currentUserId) {
     return queue;
   }
-  if (queue.some((p) => p.noteId === payload.noteId)) return queue;
+  if (isReply(payload) && typeof payload.replyId !== "number") return queue;
+  const key = payloadKey(payload);
+  if (queue.some((p) => payloadKey(p) === key)) return queue;
   return [...queue, payload];
 }
 
@@ -35,28 +71,35 @@ export function applyEnqueue(
  * suppression rules in {@link applyEnqueue} so the two stay in sync.
  */
 export function shouldEnqueueNote(
-  queue: IncomingNotePayload[],
-  payload: IncomingNotePayload,
+  queue: PopupPayload[],
+  payload: PopupPayload,
   currentUserId: number | null,
 ): boolean {
   if (!payload || typeof payload.noteId !== "number") return false;
   if (currentUserId != null && payload.senderUserId === currentUserId) {
     return false;
   }
-  if (queue.some((p) => p.noteId === payload.noteId)) return false;
+  if (isReply(payload) && typeof payload.replyId !== "number") return false;
+  const key = payloadKey(payload);
+  if (queue.some((p) => payloadKey(p) === key)) return false;
   return true;
 }
 
 /**
- * Pop the head of the queue if `noteId` matches it; otherwise filter it
- * out from anywhere it appears. Pure for testability.
+ * Pop the head of the queue if its identity matches; otherwise filter
+ * the matching entry out from anywhere it appears. Pure for testability.
+ *
+ * Accepts either a noteId (for note entries) or `{ replyId }` (for
+ * reply entries) so callers can dismiss either variant unambiguously.
  */
 export function applyDismiss(
-  queue: IncomingNotePayload[],
-  noteId: number,
-): IncomingNotePayload[] {
+  queue: PopupPayload[],
+  target: number | { replyId: number },
+): PopupPayload[] {
   if (queue.length === 0) return queue;
-  if (queue[0].noteId === noteId) return queue.slice(1);
-  const next = queue.filter((p) => p.noteId !== noteId);
+  const key =
+    typeof target === "number" ? `note:${target}` : `reply:${target.replyId}`;
+  if (payloadKey(queue[0]) === key) return queue.slice(1);
+  const next = queue.filter((p) => payloadKey(p) !== key);
   return next.length === queue.length ? queue : next;
 }

artifacts/tx-os/src/locales/ar.json

@@ -1095,13 +1095,18 @@
     "popup": {
       "heading": "ملاحظة جديدة من {{name}}",
       "headingNoSender": "وصلتك ملاحظة جديدة",
+      "replyHeading": "{{name}} ردّ على ملاحظتك",
+      "replyHeadingNoSender": "وصلك رد جديد على ملاحظتك",
       "untitled": "(بدون عنوان)",
       "queueMore_one": "ملاحظة أخرى بالانتظار",
       "queueMore_other": "{{count}} ملاحظات أخرى بالانتظار",
       "reply": "رد",
+      "replyBack": "رد عليه",
       "markRead": "تحديد كمقروءة",
       "openInNotes": "فتح في الملاحظات",
-      "dismiss": "إغلاق"
+      "openThread": "فتح المحادثة",
+      "dismiss": "إغلاق",
+      "dragHint": "اسحب للتحريك"
     },
     "confirmSendTitle": "إرسال هذه الملاحظة؟",
     "confirmSendBody_one": "سيتم إرسال هذه الملاحظة إلى شخص واحد.",

artifacts/tx-os/src/locales/en.json

@@ -1001,13 +1001,18 @@
     "popup": {
       "heading": "New note from {{name}}",
       "headingNoSender": "You received a new note",
+      "replyHeading": "{{name}} replied to your note",
+      "replyHeadingNoSender": "New reply to your note",
       "untitled": "(no title)",
       "queueMore_one": "{{count}} more note waiting",
       "queueMore_other": "{{count}} more notes waiting",
       "reply": "Reply",
+      "replyBack": "Reply back",
       "markRead": "Mark as read",
       "openInNotes": "Open in Notes",
-      "dismiss": "Dismiss"
+      "openThread": "Open thread",
+      "dismiss": "Dismiss",
+      "dragHint": "Drag to move"
     },
     "confirmSendTitle": "Send this note?",
     "confirmSendBody_one": "This note will be sent to {{count}} person.",

artifacts/tx-os/tests/notes-popup-on-receive.spec.mjs

@@ -87,6 +87,9 @@ async function loginViaUi(page, username) {
 test("recipient sees a popup modal when a note arrives in real time", async ({
   browser,
 }) => {
+  // Two-context flow with socket warmup + login UI + send confirmation
+  // routinely runs ~25-35s; default 30s leaves no margin.
+  test.setTimeout(90_000);
   const sender = await createUser("popup_sender", "Popup Sender");
   const recipient = await createUser("popup_recipient", "Popup Recipient");
 
@@ -158,7 +161,7 @@ test("recipient sees a popup modal when a note arrives in real time", async ({
     await sendPromise;
     const sendCompletedAt = Date.now();
 
-    // ---- Recipient should now see the popup modal ----
+    // ---- Recipient should now see the floating popup card ----
     // Real-time SLA: socket-fanout popup must surface within ~3s of the
     // send returning. Anything slower defeats the "can't miss it" goal.
     const popup = recipientPage.getByTestId("incoming-note-popup");
@@ -167,6 +170,15 @@ test("recipient sees a popup modal when a note arrives in real time", async ({
     await expect(popup).toContainText(noteTitle);
     await expect(popup).toContainText(noteContent);
     await expect(popup).toContainText(sender.displayEn);
+    // Floating card — NOT a modal: must not render as an alertdialog
+    // and must not block clicks behind it (no full-viewport overlay).
+    await expect(popup).toHaveAttribute("data-popup-kind", "note");
+    await expect(recipientPage.locator('[role="alertdialog"]')).toHaveCount(0);
+    // The drag handle is the only pointer-event surface that initiates
+    // a drag; presence is enough to confirm the floating-card affordance.
+    await expect(
+      recipientPage.getByTestId("incoming-note-popup-drag-handle"),
+    ).toBeVisible();
 
     // Sender does NOT see their own popup.
     await expect(senderPage.getByTestId("incoming-note-popup")).toHaveCount(0);
@@ -215,3 +227,151 @@ test("recipient sees a popup modal when a note arrives in real time", async ({
     await recipientCtx.close();
   }
 });
+
+// Task #410: when the recipient replies on a note, the *original sender*
+// (note owner) should see the same floating-card popup variant — pre-
+// filled with the reply text + replier name — wherever they are in the
+// app, with the same chime/vibration profile as the new-note alert.
+test("sender sees a floating reply card when the recipient replies", async ({
+  browser,
+}) => {
+  // Even longer than the new-note test: TWO send flows + reply submit +
+  // socket warmups across two contexts.
+  test.setTimeout(120_000);
+  const sender = await createUser("reply_sender", "Reply Sender");
+  const recipient = await createUser("reply_recipient", "Reply Recipient");
+
+  const senderCtx = await browser.newContext();
+  const recipientCtx = await browser.newContext();
+  const senderPage = await senderCtx.newPage();
+  const recipientPage = await recipientCtx.newPage();
+
+  try {
+    // Sender composes + sends the original note.
+    await loginViaUi(senderPage, sender.username);
+    await senderPage.goto("/notes");
+    await expect(senderPage.getByTestId("notes-page")).toBeVisible();
+
+    const noteTitle = `Reply Note ${uniq()}`;
+    const noteContent = "Please reply with your thoughts.";
+    await senderPage.getByTestId("notes-composer-open").click();
+    await senderPage.getByTestId("notes-composer-title").fill(noteTitle);
+    await senderPage.getByTestId("notes-composer-content").fill(noteContent);
+    const createPromise = senderPage.waitForResponse(
+      (r) =>
+        new URL(r.url()).pathname === "/api/notes" &&
+        r.request().method() === "POST" &&
+        r.status() >= 200 &&
+        r.status() < 300,
+      { timeout: 15_000 },
+    );
+    await senderPage.getByTestId("notes-composer-save").click();
+    const createResp = await createPromise;
+    const createdNote = await createResp.json();
+    createdNoteIds.push(createdNote.id);
+
+    const card = senderPage.getByTestId(`note-card-${createdNote.id}`);
+    await expect(card).toBeVisible();
+    await card.hover();
+    await senderPage.getByTestId(`note-card-send-${createdNote.id}`).click();
+    await expect(senderPage.getByTestId("send-note-dialog")).toBeVisible();
+    await senderPage
+      .getByTestId("send-note-search")
+      .fill(recipient.displayEn);
+    await senderPage
+      .getByTestId(`send-recipient-option-${recipient.id}`)
+      .click();
+    const sendPromise = senderPage.waitForResponse(
+      (r) =>
+        new URL(r.url()).pathname === `/api/notes/${createdNote.id}/send` &&
+        r.request().method() === "POST" &&
+        r.status() >= 200 &&
+        r.status() < 300,
+      { timeout: 15_000 },
+    );
+    await senderPage.getByTestId("send-note-submit").click();
+    await expect(senderPage.getByTestId("send-note-confirm")).toBeVisible();
+    await senderPage.getByTestId("send-note-confirm-submit").click();
+    await sendPromise;
+
+    // Sender navigates AWAY from /notes to prove the reply popup
+    // surfaces wherever they are — same guarantee as the new-note popup.
+    await senderPage.goto("/");
+    await senderPage.evaluate(() => {
+      window.__txosNotifPlayCount = 0;
+      window.__txosNotifLastSound = undefined;
+    });
+    await senderPage.waitForTimeout(3500); // socket warmup window
+
+    // Recipient signs in, opens the inbox, replies on the thread.
+    await loginViaUi(recipientPage, recipient.username);
+    await recipientPage.goto(`/notes?thread=${createdNote.id}&reply=1`);
+
+    const replyText = `Reply body ${uniq()}`;
+    const replyInput = recipientPage.getByTestId("thread-reply-input");
+    await expect(replyInput).toBeVisible({ timeout: 10_000 });
+    await replyInput.fill(replyText);
+    const replyPromise = recipientPage.waitForResponse(
+      (r) =>
+        new URL(r.url()).pathname ===
+          `/api/notes/${createdNote.id}/replies` &&
+        r.request().method() === "POST" &&
+        r.status() >= 200 &&
+        r.status() < 300,
+      { timeout: 15_000 },
+    );
+    await recipientPage.getByTestId("thread-reply-submit").click();
+    await replyPromise;
+    const replySentAt = Date.now();
+
+    // ---- Original sender sees the floating REPLY card ----
+    const popup = senderPage.getByTestId("incoming-note-popup");
+    await expect(popup).toBeVisible({ timeout: 5_000 });
+    expect(Date.now() - replySentAt).toBeLessThan(5_000);
+    await expect(popup).toHaveAttribute("data-popup-kind", "reply");
+    await expect(popup).toContainText(replyText);
+    await expect(popup).toContainText(recipient.displayEn);
+    // Same floating-card guarantees: no modal backdrop, drag handle present.
+    await expect(senderPage.locator('[role="alertdialog"]')).toHaveCount(0);
+    await expect(
+      senderPage.getByTestId("incoming-note-popup-drag-handle"),
+    ).toBeVisible();
+    // Reply card uses the "open thread" + "reply back" affordances —
+    // the recipient-only "mark read" action MUST be absent.
+    await expect(
+      senderPage.getByTestId("incoming-note-popup-mark-read"),
+    ).toHaveCount(0);
+    await expect(
+      senderPage.getByTestId("incoming-note-popup-open"),
+    ).toBeVisible();
+    await expect(
+      senderPage.getByTestId("incoming-note-popup-reply"),
+    ).toBeVisible();
+
+    // Same chime profile as new-note alert: notes channel, "knock" sound,
+    // exactly one play (deduped by replyId).
+    await expect
+      .poll(
+        async () =>
+          senderPage.evaluate(() => window.__txosNotifPlayCount ?? 0),
+        { timeout: 5_000 },
+      )
+      .toBeGreaterThanOrEqual(1);
+    const lastSound = await senderPage.evaluate(
+      () => window.__txosNotifLastSound,
+    );
+    expect(lastSound).toBe("knock");
+
+    // The replier (recipient) does NOT see their own outgoing reply card.
+    await expect(
+      recipientPage.getByTestId("incoming-note-popup"),
+    ).toHaveCount(0);
+
+    // Dismiss closes the floating card.
+    await senderPage.getByTestId("incoming-note-popup-dismiss").click();
+    await expect(popup).toBeHidden();
+  } finally {
+    await senderCtx.close();
+    await recipientCtx.close();
+  }
+});