fix(board): stop every successful drag from snapping back

The effect that syncs server state re-ran whenever `busy` flipped, which it
does at the end of every drag. It then called setCards(initialCards) with
the snapshot it already had — the server had not re-rendered — discarding
the optimistic move. The card visibly returned to its original column while
the database held the correct value.

Tracks the last adopted snapshot in a ref so the effect only acts on a
genuinely new one, and calls router.refresh() after a successful move so a
new snapshot actually arrives.

Also hardens the timeline drag: the pointerup handler compared against
`dragging` state, which updates asynchronously, so it could read the
pre-drag value and return early with the drag never committing and no error
anywhere. Reads a ref instead, and clears on pointercancel.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/components/board/board.tsx

@@ -1,6 +1,7 @@
 "use client";
 
-import { useEffect, useMemo, useState } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
+import { useRouter } from "next/navigation";
 import {
   DndContext,
   DragOverlay,
@@ -132,11 +133,27 @@ export function Board({
 
   const activeCard = activeId ? cards.find((c) => c.id === activeId) : null;
 
+  const router = useRouter();
   const busy = activeId !== null || saving;
 
   useRefreshOnFocus(busy);
 
+  /**
+   * The last server snapshot we adopted.
+   *
+   * Load-bearing. Without it this effect re-runs whenever `busy` flips — which
+   * it does at the end of every successful drag — and calls
+   * `setCards(initialCards)` with the snapshot we ALREADY had, because the
+   * server has not re-rendered yet. The optimistic move is discarded and the
+   * card visibly snaps back to where it started, on every single drag, while
+   * the database is perfectly correct.
+   */
+  const lastSynced = useRef(initialCards);
+
   useEffect(() => {
+    // Only adopt a genuinely new snapshot, never a re-run caused by `busy`.
+    if (initialCards === lastSynced.current) return;
+    lastSynced.current = initialCards;
     if (!busy) setCards(initialCards);
   }, [initialCards, busy]);
 
@@ -202,6 +219,11 @@ export function Board({
       if (!response.ok) {
         console.error("[board] move failed", response.status);
         setCards(previous);
+      } else {
+        // Pull the new server snapshot so `initialCards` reflects the move.
+        // Without this the optimistic state is the only record of it, and the
+        // next genuine refresh — a focus event, a navigation — would revert it.
+        router.refresh();
       }
     } catch (error) {
       console.error("[board] move failed", error);

src/components/roadmap/timeline-view.tsx

@@ -29,6 +29,8 @@ export function TimelineView({
 }) {
   const trackRef = useRef<HTMLDivElement>(null);
   const [dragging, setDragging] = useState<string | null>(null);
+  /** Read by the pointer handlers; `dragging` is only for the visual state. */
+  const draggingRef = useRef<string | null>(null);
 
   const dated = cards.filter((card) => card.targetDate);
   const undated = cards.filter((card) => !card.targetDate);
@@ -157,7 +159,14 @@ export function TimelineView({
                     onPointerDown={
                       canReschedule
                         ? (event) => {
+                            event.preventDefault();
                             event.currentTarget.setPointerCapture(event.pointerId);
+                            // The ref, not the state, is what the pointerup
+                            // handler reads. State updates are asynchronous, so
+                            // a handler comparing against `dragging` can still
+                            // see the pre-drag value and return early — the drag
+                            // would then never commit, with no error anywhere.
+                            draggingRef.current = item.id;
                             setDragging(item.id);
                           }
                         : undefined
@@ -165,8 +174,10 @@ export function TimelineView({
                     onPointerUp={
                       canReschedule
                         ? (event) => {
-                            if (dragging !== item.id) return;
+                            if (draggingRef.current !== item.id) return;
+                            draggingRef.current = null;
                             setDragging(null);
+
                             const date = dateAt(event.clientX);
                             if (date && date !== card.targetDate.slice(0, 10)) {
                               onReschedule(item.id, date);
@@ -174,6 +185,17 @@ export function TimelineView({
                           }
                         : undefined
                     }
+                    onPointerCancel={
+                      canReschedule
+                        ? () => {
+                            // A cancelled pointer must clear the drag, or the
+                            // bar stays visually held and the next click on it
+                            // is swallowed.
+                            draggingRef.current = null;
+                            setDragging(null);
+                          }
+                        : undefined
+                    }
                     className={`absolute flex items-center overflow-hidden rounded-full px-2 text-[11px] ${
                       overdue ? "bg-accent text-accent-fg" : "bg-brand text-brand-fg"
                     } ${canReschedule ? "cursor-ew-resize" : ""} ${