feat(10-11): add click-after-drag guard + teleport folder picker to StorageBrowser

- Guard file-row click: draggingFile ? null : emit('file-open', file)
- Add onFileDragEnd() with nextTick reset to prevent click-after-drag navigation
- Update onDropDocOnFolder to defer draggingFile reset via await nextTick()
- Replace absolute folder picker with Teleport to body + getBoundingClientRect positioning
- Add scroll/resize listeners to reposition picker on window scroll
- All 6 UX-11 dragmove tests now pass

frontend/src/components/storage/StorageBrowser.vue

@@ -141,9 +141,9 @@
           :draggable="mode === 'local'"
           class="px-4 py-2.5 grid grid-cols-[2rem_1fr_6rem_8rem_6rem] gap-3 items-center hover:bg-gray-50 group cursor-pointer transition-colors select-none"
           :class="{ 'opacity-50': draggingFile?.id === file.id }"
-          @click="$emit('file-open', file)"
+          @click="draggingFile ? null : $emit('file-open', file)"
           @dragstart="mode === 'local' ? onFileDragStart(file, $event) : null"
-          @dragend="draggingFile = null; dragOverFolderId = null"
+          @dragend="onFileDragEnd"
         >
           <div class="w-7 h-7 bg-indigo-50 rounded-lg flex items-center justify-center shrink-0">
             <svg class="w-4 h-4 text-indigo-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -185,7 +185,7 @@
               <!-- Move -->
               <div class="relative">
                 <button
-                  @click.stop="folderPickerFileId = folderPickerFileId === file.id ? null : file.id"
+                  @click.stop="openFolderPicker(file.id, $event)"
                   title="Move to folder"
                   class="p-1.5 rounded hover:bg-gray-200 text-gray-400 hover:text-gray-700 transition-colors"
                 >
@@ -194,23 +194,6 @@
                       d="M3 7a2 2 0 012-2h4l2 2h8a2 2 0 012 2v8a2 2 0 01-2 2H5a2 2 0 01-2-2V7z" />
                   </svg>
                 </button>
-                <div
-                  v-if="folderPickerFileId === file.id"
-                  class="absolute right-0 top-full mt-1 w-48 bg-white border border-gray-200 rounded-xl shadow-lg z-20 py-1"
-                  @click.stop
-                >
-                  <button class="w-full text-left px-3 py-2 text-sm text-gray-600 hover:bg-gray-50"
-                    @click.stop="$emit('file-move', { fileId: file.id, folderId: null }); folderPickerFileId = null">
-                    Root (no folder)
-                  </button>
-                  <button
-                    v-for="f in rootFolders"
-                    :key="f.id"
-                    class="w-full text-left px-3 py-2 text-sm text-gray-700 hover:bg-indigo-50 hover:text-indigo-700 truncate"
-                    @click.stop="$emit('file-move', { fileId: file.id, folderId: f.id }); folderPickerFileId = null"
-                  >{{ f.name }}</button>
-                  <p v-if="!rootFolders.length" class="px-3 py-2 text-xs text-gray-400">No folders yet</p>
-                </div>
               </div>
               <!-- Delete -->
               <button @click.stop="$emit('file-delete', file.id)" title="Delete"
@@ -267,6 +250,32 @@
       </div>
     </div>
   </div>
+
+  <!-- Teleported folder picker — avoids overflow:hidden clipping -->
+  <Teleport to="body">
+    <div
+      v-if="folderPickerFileId"
+      :style="pickerStyle"
+      data-test="folder-picker"
+      class="fixed z-[9999] bg-white border border-gray-200 rounded-xl shadow-lg overflow-y-auto py-1"
+      style="max-height: 240px;"
+      @click.stop
+    >
+      <button
+        class="w-full text-left px-3 py-2 text-sm text-gray-600 hover:bg-gray-50"
+        @click.stop="$emit('file-move', { fileId: folderPickerFileId, folderId: null }); folderPickerFileId = null"
+      >
+        Root (no folder)
+      </button>
+      <button
+        v-for="f in rootFolders"
+        :key="f.id"
+        class="w-full text-left px-3 py-2 text-sm text-gray-700 hover:bg-indigo-50 hover:text-indigo-700 truncate"
+        @click.stop="$emit('file-move', { fileId: folderPickerFileId, folderId: f.id }); folderPickerFileId = null"
+      >{{ f.name }}</button>
+      <p v-if="!rootFolders.length" class="px-3 py-2 text-xs text-gray-400">No folders yet</p>
+    </div>
+  </Teleport>
 </template>
 
 <script setup>
@@ -385,22 +394,80 @@ function onFolderDragOver(folderId, e) {
   dragOverFolderId.value = folderId
 }
 
+function onFileDragEnd() {
+  dragOverFolderId.value = null
+  nextTick(() => { draggingFile.value = null })
+}
+
 async function onDropDocOnFolder(folderId) {
   if (!draggingFile.value) return
   const fileId = draggingFile.value.id
-  draggingFile.value = null
   dragOverFolderId.value = null
   emit('file-move', { fileId, folderId })
+  await nextTick()
+  draggingFile.value = null
 }
 
-// ── Move folder picker ────────────────────────────────────────────────────────
+// ── Move folder picker (Teleport + getBoundingClientRect) ─────────────────────
 
 const folderPickerFileId = ref(null)
+const pickerStyle = ref({})
+// Map fileId → trigger button element, so scroll listener can reposition
+const pickerTriggerMap = new Map()
 
-function onOutsideClick(e) {
-  if (!e.target.closest('.relative')) folderPickerFileId.value = null
+function updatePickerPosition(rect) {
+  const spaceBelow = window.innerHeight - rect.bottom
+  const dropH = 240
+  if (spaceBelow >= dropH || spaceBelow > 120) {
+    pickerStyle.value = {
+      top: `${rect.bottom + 4}px`,
+      left: `${rect.left}px`,
+      width: '192px',
+    }
+  } else {
+    pickerStyle.value = {
+      bottom: `${window.innerHeight - rect.top + 4}px`,
+      left: `${rect.left}px`,
+      width: '192px',
+    }
+  }
 }
 
-onMounted(() => document.addEventListener('click', onOutsideClick))
-onUnmounted(() => document.removeEventListener('click', onOutsideClick))
+function openFolderPicker(fileId, ev) {
+  // Toggle off if same file
+  if (folderPickerFileId.value === fileId) {
+    folderPickerFileId.value = null
+    return
+  }
+  folderPickerFileId.value = fileId
+  const trigger = ev.currentTarget
+  pickerTriggerMap.set(fileId, trigger)
+  updatePickerPosition(trigger.getBoundingClientRect())
+}
+
+function onWindowScroll() {
+  if (!folderPickerFileId.value) return
+  const trig = pickerTriggerMap.get(folderPickerFileId.value)
+  if (trig) updatePickerPosition(trig.getBoundingClientRect())
+}
+
+function onOutsideClick(e) {
+  if (
+    !e.target.closest('[data-test="folder-picker"]') &&
+    !e.target.closest('.relative')
+  ) {
+    folderPickerFileId.value = null
+  }
+}
+
+onMounted(() => {
+  document.addEventListener('click', onOutsideClick)
+  window.addEventListener('scroll', onWindowScroll, true)
+  window.addEventListener('resize', onWindowScroll)
+})
+onUnmounted(() => {
+  document.removeEventListener('click', onOutsideClick)
+  window.removeEventListener('scroll', onWindowScroll, true)
+  window.removeEventListener('resize', onWindowScroll)
+})
 </script>