Much simpler undo/redo handling, bugs fixed and less code.

src/components/EventOverlay.vue

@@ -314,7 +314,46 @@ function startLocalDrag(init, evt) {
     realizedId: null,
   }
 
-  store.$history?.beginCompound()
+  // If history is empty (no baseline), create a baseline snapshot BEFORE any movement mutations
+  try {
+    const isResize = init.mode === 'resize-left' || init.mode === 'resize-right'
+    // Move: only baseline if history empty. Resize: force baseline (so undo returns to pre-resize) but only once.
+    store.$history?._baselineIfNeeded?.(isResize)
+    const evs = []
+    if (store.events instanceof Map) {
+      for (const [id, ev] of store.events) {
+        evs.push({
+          id,
+          start: ev.startDate,
+          days: ev.days,
+          title: ev.title,
+          color: ev.colorId,
+          recur: ev.recur
+            ? {
+                f: ev.recur.freq,
+                i: ev.recur.interval,
+                c: ev.recur.count,
+                w: Array.isArray(ev.recur.weekdays) ? ev.recur.weekdays.join('') : null,
+              }
+            : null,
+        })
+      }
+    }
+    console.debug(
+      isResize ? '[history] pre-resize baseline snapshot' : '[history] pre-drag baseline snapshot',
+      {
+        mode: init.mode,
+        events: evs,
+        weekend: store.weekend,
+        firstDay: store.config?.first_day,
+      },
+    )
+  } catch {}
+
+  // Enter drag suppression (prevent intermediate pushes)
+  try {
+    store.$history?._beginDrag?.()
+  } catch {}
 
   if (evt.currentTarget && evt.pointerId !== undefined) {
     try {
@@ -453,7 +492,10 @@ function onDragPointerUp(e) {
       justDragged.value = false
     }, 120)
   }
-  store.$history?.endCompound()
+  // End drag suppression regardless; no post snapshot (pre-only model)
+  try {
+    store.$history?._endDrag?.()
+  } catch {}
 }
 
 const min = (a, b) => (a < b ? a : b)