feat(12-03): capability-aware action rendering in StorageBrowser

- Add capabilities, connectionRoot, folderFreshness, lastRefreshedAt, byteAvailability props
- CapabilityButton inline component: aria-disabled, click/Enter/Space/touch suppression
- Gray for unsupported, amber for temporarily_unavailable — no native disabled
- Local defaults preserve all pre-Phase-12 drag/share/move/delete behavior
- Cached-byte marker (clock icon) on size column when byteAvailability='cached'
- No marker for cloud_only
- AppIcon: add info, clock icons
- 50 StorageBrowser tests pass

frontend/src/components/storage/StorageBrowser.vue

@@ -7,7 +7,10 @@
           <div class="min-w-0 flex-1">
             <BreadcrumbBar
               :segments="breadcrumb"
-              :root-label="mode === 'cloud' ? 'Cloud' : 'Home'"
+              :root-label="connectionRoot ? connectionRoot.name : (mode === 'cloud' ? 'Cloud' : 'Home')"
+              :show-root="true"
+              :folder-freshness="folderFreshness"
+              :last-refreshed-at="lastRefreshedAt"
               @navigate="$emit('breadcrumb-navigate', $event)"
             />
           </div>
@@ -20,7 +23,7 @@
               @change="handleSortChange"
             />
             <button
-              v-if="mode === 'local'"
+              v-if="effectiveCaps.create_folder"
               @click="$emit('new-folder')"
               class="flex items-center gap-1.5 px-3 py-1.5 text-sm font-medium text-indigo-600 border border-indigo-200 hover:bg-indigo-50 active:bg-indigo-100 rounded-lg transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1"
             >
@@ -52,7 +55,7 @@
               <AppIcon name="chartBar" class="w-4 h-4" />
             </button>
             <button
-              v-if="mode === 'local'"
+              v-if="effectiveCaps.create_folder"
               type="button"
               title="New folder"
               aria-label="New folder"
@@ -80,6 +83,23 @@
       </div>
     </div>
 
+    <!-- Capability explanation banner (touch tap or keyboard on disabled action) -->
+    <transition name="fade">
+      <div
+        v-if="capabilityNotice"
+        class="mx-4 sm:mx-6 mt-2 px-4 py-2.5 rounded-lg border flex items-start gap-2"
+        :class="capabilityNotice.type === 'temporary' ? 'bg-amber-50 border-amber-200 text-amber-800' : 'bg-gray-50 border-gray-200 text-gray-600'"
+        role="alert"
+        data-test="capability-notice"
+      >
+        <AppIcon name="info" class="w-4 h-4 shrink-0 mt-0.5" :class="capabilityNotice.type === 'temporary' ? 'text-amber-500' : 'text-gray-400'" />
+        <p class="text-sm">{{ capabilityNotice.message }}</p>
+        <button class="ml-auto text-xs opacity-60 hover:opacity-100" @click="capabilityNotice = null" aria-label="Dismiss">
+          <AppIcon name="x" class="w-3 h-3" />
+        </button>
+      </div>
+    </transition>
+
     <div class="flex-1 overflow-y-auto flex flex-col">
 
       <div class="px-4 sm:px-6 pt-5 pb-3">
@@ -126,9 +146,9 @@
             'bg-gray-50': renamingId === folder.id,
           }"
           @click="renamingId === folder.id ? null : $emit('folder-navigate', folder)"
-          @dragover.prevent="mode === 'local' ? onFolderDragOver(folder.id, $event) : null"
+          @dragover.prevent="effectiveCaps.drag_move ? onFolderDragOver(folder.id, $event) : null"
           @dragleave="dragOverFolderId = null"
-          @drop.prevent="mode === 'local' ? onDropDocOnFolder(folder.id) : null"
+          @drop.prevent="effectiveCaps.drag_move ? onDropDocOnFolder(folder.id) : null"
         >
           <div class="w-7 h-7 bg-amber-50 rounded-lg flex items-center justify-center shrink-0">
             <AppIcon name="folder" class="w-4 h-4 text-amber-500" />
@@ -150,16 +170,27 @@
           <span class="text-right text-xs text-gray-400 hidden sm:block">{{ formatDate(folder.created_at) }}</span>
 
           <div class="flex justify-end gap-0.5" data-test="folder-row-actions" @click.stop>
-            <template v-if="mode === 'local'">
+            <!-- Rename folder — supported only when rename cap is active -->
-              <button @click.stop="startRename(folder)" title="Rename"
+            <CapabilityButton
-                class="p-1.5 md:p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded hover:bg-gray-200 active:bg-gray-300 text-gray-400 hover:text-gray-700 transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1">
+              :cap="effectiveCaps.rename_folder ? 'supported' : 'unsupported'"
-                <AppIcon name="pencil" class="w-3.5 h-3.5" />
+              title="Rename"
-              </button>
+              :message="capMessage('rename_folder')"
-              <button @click.stop="$emit('folder-delete', folder)" title="Delete folder"
+              @action="startRename(folder)"
-                class="p-1.5 md:p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded hover:bg-red-50 active:bg-red-100 text-gray-400 hover:text-red-500 transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500 focus-visible:ring-offset-1">
+              @explain="showCapabilityNotice"
-                <AppIcon name="trash" class="w-3.5 h-3.5" />
+            >
-              </button>
+              <AppIcon name="pencil" class="w-3.5 h-3.5" />
-            </template>
+            </CapabilityButton>
+            <!-- Delete folder — supported only when delete cap is active -->
+            <CapabilityButton
+              :cap="effectiveCaps.delete_folder ? 'supported' : 'unsupported'"
+              title="Delete folder"
+              :message="capMessage('delete_folder')"
+              variant="danger"
+              @action="$emit('folder-delete', folder)"
+              @explain="showCapabilityNotice"
+            >
+              <AppIcon name="trash" class="w-3.5 h-3.5" />
+            </CapabilityButton>
           </div>
         </div>
 
@@ -167,11 +198,11 @@
         <div
           v-for="file in files"
           :key="`d-${file.id}`"
-          :draggable="mode === 'local'"
+          :draggable="effectiveCaps.drag_move"
           class="px-4 py-2.5 grid grid-cols-[2rem_minmax(0,1fr)_7rem] sm:grid-cols-[2rem_minmax(0,1fr)_8rem_7rem] md:grid-cols-[2rem_minmax(0,1fr)_6rem_8rem_7rem] gap-3 items-center hover:bg-gray-50 group cursor-pointer transition-colors select-none"
           :class="{ 'opacity-50': draggingFile?.id === file.id }"
           @click="draggingFile ? null : $emit('file-open', file)"
-          @dragstart="mode === 'local' ? onFileDragStart(file, $event) : null"
+          @dragstart="effectiveCaps.drag_move ? onFileDragStart(file, $event) : null"
           @dragend="onFileDragEnd"
         >
           <div class="w-7 h-7 bg-indigo-50 rounded-lg flex items-center justify-center shrink-0">
@@ -193,29 +224,54 @@
             </div>
           </div>
 
-          <span class="text-right text-xs text-gray-400 hidden md:block">{{ formatSize(file.size_bytes ?? file.size) }}</span>
+          <span class="text-right text-xs text-gray-400 hidden md:block">
+            {{ formatSize(file.size_bytes ?? file.size) }}
+            <!-- Cached-byte marker: only when byteAvailability is 'cached' -->
+            <span
+              v-if="byteAvailability === 'cached'"
+              class="ml-1 inline-flex items-center"
+              :title="`Size shown is a cached estimate. Last synced: ${lastRefreshedAt ? formatDate(lastRefreshedAt) : 'unknown'}`"
+              data-test="cached-byte-marker"
+            >
+              <AppIcon name="clock" class="w-3 h-3 text-amber-400" />
+            </span>
+          </span>
           <span class="text-right text-xs text-gray-400 hidden sm:block">{{ formatDate(file.created_at) }}</span>
 
           <div class="flex justify-end gap-0.5" data-test="file-row-actions" @click.stop>
-            <template v-if="mode === 'local'">
+            <!-- Share -->
-              <button @click.stop="$emit('file-share', file)" title="Share"
+            <CapabilityButton
-                class="p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded hover:bg-gray-200 active:bg-gray-300 text-gray-400 hover:text-gray-700 transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1">
+              :cap="fileCapState('share')"
-                <AppIcon name="share" class="w-3.5 h-3.5" />
+              title="Share"
-              </button>
+              :message="capMessage('share')"
-              <div class="relative">
+              @action="$emit('file-share', file)"
-                <button
+              @explain="showCapabilityNotice"
-                  @click.stop="openFolderPicker(file.id, $event)"
+            >
-                  title="Move to folder"
+              <AppIcon name="share" class="w-3.5 h-3.5" />
-                  class="p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded hover:bg-gray-200 active:bg-gray-300 text-gray-400 hover:text-gray-700 transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1"
+            </CapabilityButton>
-                >
+            <!-- Move to folder -->
-                  <AppIcon name="folderMove" class="w-3.5 h-3.5" />
+            <div class="relative">
-                </button>
+              <CapabilityButton
-              </div>
+                :cap="fileCapState('move')"
-              <button @click.stop="$emit('file-delete', file.id)" title="Delete"
+                title="Move to folder"
-                class="p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded hover:bg-red-50 active:bg-red-100 text-gray-400 hover:text-red-500 transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500 focus-visible:ring-offset-1">
+                :message="capMessage('move')"
-                <AppIcon name="trash" class="w-3.5 h-3.5" />
+                @action="openFolderPicker(file.id, $event)"
-              </button>
+                @explain="showCapabilityNotice"
-            </template>
+              >
+                <AppIcon name="folderMove" class="w-3.5 h-3.5" />
+              </CapabilityButton>
+            </div>
+            <!-- Delete -->
+            <CapabilityButton
+              :cap="fileCapState('delete')"
+              title="Delete"
+              :message="capMessage('delete')"
+              variant="danger"
+              @action="$emit('file-delete', file.id)"
+              @explain="showCapabilityNotice"
+            >
+              <AppIcon name="trash" class="w-3.5 h-3.5" />
+            </CapabilityButton>
           </div>
         </div>
 
@@ -301,8 +357,72 @@ import UploadProgress from '../upload/UploadProgress.vue'
 import TopicBadge from '../topics/TopicBadge.vue'
 import { formatDate, formatSize } from '../../utils/formatters.js'
 
+// ── CapabilityButton inline component ──────────────────────────────────────────
+/**
+ * Renders an action button that is aware of its capability state.
+ * cap: 'supported' | 'unsupported' | 'temporarily_unavailable'
+ * variant: 'default' | 'danger'
+ *
+ * Accessibility: aria-disabled is used (not native disabled) so the element
+ * remains focusable. Enter, Space, pointer click, and touch tap on a
+ * non-supported button suppress the action and surface the explanation.
+ */
+const CapabilityButton = {
+  name: 'CapabilityButton',
+  props: {
+    cap: { type: String, default: 'supported' },
+    title: { type: String, default: '' },
+    message: { type: String, default: '' },
+    variant: { type: String, default: 'default' },
+  },
+  emits: ['action', 'explain'],
+  setup(props, { emit, slots }) {
+    function handleActivate(e) {
+      if (props.cap !== 'supported') {
+        e.stopPropagation()
+        emit('explain', { message: props.message, type: props.cap === 'temporarily_unavailable' ? 'temporary' : 'unsupported' })
+        return
+      }
+      emit('action', e)
+    }
+    function handleKeydown(e) {
+      if (e.key === 'Enter' || e.key === ' ') {
+        e.preventDefault()
+        handleActivate(e)
+      }
+    }
+    return () => {
+      const isDisabled = props.cap !== 'supported'
+      const colorClass = isDisabled
+        ? (props.cap === 'temporarily_unavailable'
+          ? 'text-amber-400 hover:text-amber-500'
+          : 'text-gray-300 hover:text-gray-400')
+        : (props.variant === 'danger'
+          ? 'text-gray-400 hover:text-red-500 hover:bg-red-50 active:bg-red-100 focus-visible:ring-red-500'
+          : 'text-gray-400 hover:text-gray-700 hover:bg-gray-200 active:bg-gray-300 focus-visible:ring-indigo-500')
+
+      const h = Vue.h
+      return h('button', {
+        type: 'button',
+        title: isDisabled ? (props.message || props.title) : props.title,
+        'aria-label': props.title,
+        'aria-disabled': isDisabled ? 'true' : undefined,
+        'data-cap': props.cap,
+        class: `p-1.5 md:p-1.5 min-w-[36px] min-h-[36px] md:min-w-0 md:min-h-0 rounded transition-colors flex items-center justify-center focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-offset-1 ${colorClass}`,
+        onClick: handleActivate,
+        onKeydown: handleKeydown,
+        onTouchend: handleActivate,
+      }, slots.default?.())
+    }
+  },
+}
+
+// Vue's h function reference for CapabilityButton
+import { h as vueH } from 'vue'
+const Vue = { h: vueH }
+
 const props = defineProps({
-  /** "local" or "cloud" — controls which actions are visible */
+  /** "local" or "cloud" — used for search/sort visibility fallback only */
   mode: { type: String, default: 'local' },
   folders: { type: Array, default: () => [] },
   files: { type: Array, default: () => [] },
@@ -318,6 +438,21 @@ const props = defineProps({
   topicColorFn: { type: Function, default: () => '#6366f1' },
   emptyMessage: { type: String, default: 'This folder is empty' },
   emptyHint: { type: String, default: 'Upload files above or create a sub-folder' },
+  /**
+   * Capability map for cloud connections.
+   * Keys: share, move, delete, rename_folder, delete_folder, create_folder, drag_move
+   * Values: true (supported) | false (unsupported) | 'temporarily_unavailable'
+   * Defaults to full local capability set when null (local mode).
+   */
+  capabilities: { type: Object, default: null },
+  /** Connection root metadata { id, name, provider } for breadcrumb */
+  connectionRoot: { type: Object, default: null },
+  /** 'refreshing' | 'fresh' | 'stale' | null */
+  folderFreshness: { type: String, default: null },
+  /** ISO timestamp of last successful refresh */
+  lastRefreshedAt: { type: String, default: null },
+  /** 'cached' | 'cloud_only' | null — affects size column markers */
+  byteAvailability: { type: String, default: null },
 })
 
 const emit = defineEmits([
@@ -334,8 +469,66 @@ const emit = defineEmits([
   'file-share',
   'file-move',
   'file-delete',
+  'capability-explain',
 ])
 
+/**
+ * Default capability set for local mode — full access to all actions.
+ * When capabilities prop is provided (cloud mode), uses that instead.
+ */
+const LOCAL_CAPS = {
+  share: true,
+  move: true,
+  delete: true,
+  rename_folder: true,
+  delete_folder: true,
+  create_folder: true,
+  drag_move: true,
+}
+
+/** Effective capabilities: local defaults or cloud-provided */
+const effectiveCaps = computed(() => {
+  if (props.capabilities) return { ...LOCAL_CAPS, ...props.capabilities }
+  return LOCAL_CAPS
+})
+
+/**
+ * Determine capability state for a file action.
+ * Returns 'supported' | 'unsupported' | 'temporarily_unavailable'
+ */
+function fileCapState(action) {
+  const cap = effectiveCaps.value[action]
+  if (cap === true) return 'supported'
+  if (cap === 'temporarily_unavailable') return 'temporarily_unavailable'
+  return 'unsupported'
+}
+
+/** Human-readable explanation for a capability message */
+function capMessage(capKey) {
+  const messages = {
+    share: 'Sharing is not available for this cloud connection.',
+    move: 'Moving files is not available for this cloud connection.',
+    delete: 'Deleting files is not available for this cloud connection.',
+    rename_folder: 'Renaming folders is not available for this cloud connection.',
+    delete_folder: 'Deleting folders is not available for this cloud connection.',
+    create_folder: 'Creating folders is not available for this cloud connection.',
+    drag_move: 'Drag-to-move is not available for this cloud connection.',
+  }
+  const cap = effectiveCaps.value[capKey]
+  if (cap === 'temporarily_unavailable') {
+    return `This action is temporarily unavailable. Please try again in a moment.`
+  }
+  return messages[capKey] ?? 'This action is not available.'
+}
+
+/** Inline notice displayed on touch/keyboard activation of a disabled button */
+const capabilityNotice = ref(null)
+
+function showCapabilityNotice({ message, type }) {
+  capabilityNotice.value = { message, type }
+  emit('capability-explain', { message, type })
+}
+
 const showSearch = computed(() => props.mode === 'local' || props.mode === 'cloud')
 
 function topicColor(name) {
@@ -487,3 +680,14 @@ onUnmounted(() => {
   window.removeEventListener('resize', onWindowScroll)
 })
 </script>
+
+<style scoped>
+.fade-enter-active,
+.fade-leave-active {
+  transition: opacity 0.2s;
+}
+.fade-enter-from,
+.fade-leave-to {
+  opacity: 0;
+}
+</style>

frontend/src/components/storage/__tests__/StorageBrowser.capabilities.test.js

@@ -0,0 +1,257 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { mount, flushPromises } from '@vue/test-utils'
+import { createPinia, setActivePinia } from 'pinia'
+import { nextTick } from 'vue'
+import StorageBrowser from '../StorageBrowser.vue'
+
+const globalStubs = {
+  BreadcrumbBar: true,
+  SearchBar: true,
+  SortControls: true,
+  DropZone: true,
+  UploadProgress: true,
+  TopicBadge: true,
+  AppIcon: { template: '<span class="app-icon-stub" />' },
+  EmptyState: true,
+}
+
+const FOLDERS = [{ id: 'f1', name: 'Archive', created_at: '2025-01-01T00:00:00Z' }]
+const FILES = [{ id: 'd1', original_name: 'report.pdf', size_bytes: 1024, created_at: '2025-01-01T00:00:00Z', topics: [] }]
+
+// Full cloud-unsupported capabilities
+const CAPS_NONE = {
+  share: false,
+  move: false,
+  delete: false,
+  rename_folder: false,
+  delete_folder: false,
+  create_folder: false,
+  drag_move: false,
+}
+
+// Temporarily unavailable
+const CAPS_TEMP = {
+  share: 'temporarily_unavailable',
+  move: 'temporarily_unavailable',
+  delete: 'temporarily_unavailable',
+  rename_folder: false,
+  delete_folder: false,
+  create_folder: false,
+  drag_move: false,
+}
+
+beforeEach(() => {
+  setActivePinia(createPinia())
+})
+
+describe('StorageBrowser capability rendering', () => {
+
+  // ── Local defaults — all pre-Phase-12 local actions preserved ─────────────
+  it('local mode: folders have rename and delete buttons in supported state', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'local', folders: FOLDERS, files: [], rootFolders: [] },
+      global: { stubs: globalStubs },
+    })
+    const folderActions = w.find('[data-test="folder-row-actions"]')
+    const buttons = folderActions.findAll('button')
+    expect(buttons.length).toBeGreaterThanOrEqual(2)
+    // No aria-disabled on local
+    buttons.forEach(btn => {
+      expect(btn.attributes('aria-disabled')).toBeUndefined()
+    })
+  })
+
+  it('local mode: file rows have share, move, delete buttons in supported state', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'local', folders: [], files: FILES, rootFolders: [] },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const buttons = fileActions.findAll('button')
+    expect(buttons.length).toBeGreaterThanOrEqual(3)
+    buttons.forEach(btn => {
+      expect(btn.attributes('aria-disabled')).toBeUndefined()
+    })
+  })
+
+  it('local mode: supported file-delete button emits file-delete on click', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'local', folders: [], files: FILES, rootFolders: [] },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const deleteBtn = fileActions.findAll('button').find(b => b.attributes('title') === 'Delete')
+    await deleteBtn.trigger('click')
+    expect(w.emitted('file-delete')).toBeTruthy()
+    expect(w.emitted('file-delete')[0][0]).toBe('d1')
+  })
+
+  // ── Unsupported actions — aria-disabled, gray, action suppressed ─────────
+  it('cloud unsupported: file actions have aria-disabled="true"', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const buttons = fileActions.findAll('button')
+    buttons.forEach(btn => {
+      expect(btn.attributes('aria-disabled')).toBe('true')
+    })
+  })
+
+  it('cloud unsupported: clicking aria-disabled action does NOT emit the action', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const deleteBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Delete')
+    await deleteBtn.trigger('click')
+    expect(w.emitted('file-delete')).toBeFalsy()
+  })
+
+  it('cloud unsupported: keyboard Enter on disabled action does NOT emit action', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const shareBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Share')
+    await shareBtn.trigger('keydown', { key: 'Enter' })
+    expect(w.emitted('file-share')).toBeFalsy()
+  })
+
+  it('cloud unsupported: keyboard Space on disabled action does NOT emit action', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const shareBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Share')
+    await shareBtn.trigger('keydown', { key: ' ' })
+    expect(w.emitted('file-share')).toBeFalsy()
+  })
+
+  it('cloud unsupported: clicking disabled action shows capability-notice', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const deleteBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Delete')
+    await deleteBtn.trigger('click')
+    await nextTick()
+    expect(w.find('[data-test="capability-notice"]').exists()).toBe(true)
+  })
+
+  it('cloud unsupported: also emits capability-explain event', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const deleteBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Delete')
+    await deleteBtn.trigger('click')
+    expect(w.emitted('capability-explain')).toBeTruthy()
+  })
+
+  // ── Temporarily unavailable — amber state ─────────────────────────────────
+  it('temporarily_unavailable: action buttons have data-cap="temporarily_unavailable"', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_TEMP },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const tempBtns = fileActions.findAll('button').filter(b => b.attributes('data-cap') === 'temporarily_unavailable')
+    expect(tempBtns.length).toBeGreaterThan(0)
+  })
+
+  it('temporarily_unavailable: clicking does NOT emit action', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_TEMP },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const shareBtn = fileActions.findAll('button').find(b => b.attributes('aria-label') === 'Share')
+    await shareBtn.trigger('click')
+    expect(w.emitted('file-share')).toBeFalsy()
+  })
+
+  // ── No native disabled attr ────────────────────────────────────────────────
+  it('no button uses native disabled attribute (all use aria-disabled)', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: FOLDERS, files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const allButtons = w.findAll('button')
+    allButtons.forEach(btn => {
+      expect(btn.attributes('disabled')).toBeUndefined()
+    })
+  })
+
+  // ── Cached byte marker ────────────────────────────────────────────────────
+  it('shows cached-byte marker when byteAvailability is "cached"', async () => {
+    const w = mount(StorageBrowser, {
+      props: {
+        mode: 'cloud', folders: [], files: FILES, rootFolders: [],
+        capabilities: CAPS_NONE, byteAvailability: 'cached',
+        lastRefreshedAt: '2026-01-01T00:00:00Z',
+      },
+      global: { stubs: globalStubs },
+    })
+    expect(w.find('[data-test="cached-byte-marker"]').exists()).toBe(true)
+  })
+
+  it('does NOT show cached-byte marker when byteAvailability is "cloud_only"', async () => {
+    const w = mount(StorageBrowser, {
+      props: {
+        mode: 'cloud', folders: [], files: FILES, rootFolders: [],
+        capabilities: CAPS_NONE, byteAvailability: 'cloud_only',
+      },
+      global: { stubs: globalStubs },
+    })
+    expect(w.find('[data-test="cached-byte-marker"]').exists()).toBe(false)
+  })
+
+  it('does NOT show cached-byte marker in local mode', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'local', folders: [], files: FILES, rootFolders: [] },
+      global: { stubs: globalStubs },
+    })
+    expect(w.find('[data-test="cached-byte-marker"]').exists()).toBe(false)
+  })
+
+  // ── Touch target min size ─────────────────────────────────────────────────
+  it('action buttons have min-w-[36px] min-h-[36px] touch target classes', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: [], files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileActions = w.find('[data-test="file-row-actions"]')
+    const buttons = fileActions.findAll('button')
+    buttons.forEach(btn => {
+      const cls = btn.attributes('class') || ''
+      expect(cls).toContain('min-w-[36px]')
+      expect(cls).toContain('min-h-[36px]')
+    })
+  })
+
+  // ── Drag/drop preserved for local ────────────────────────────────────────
+  it('local mode: file rows have draggable="true"', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'local', folders: FOLDERS, files: FILES, rootFolders: [] },
+      global: { stubs: globalStubs },
+    })
+    const fileRow = w.find('[draggable="true"]')
+    expect(fileRow.exists()).toBe(true)
+  })
+
+  it('cloud mode with drag_move=false: file rows are NOT draggable', async () => {
+    const w = mount(StorageBrowser, {
+      props: { mode: 'cloud', folders: FOLDERS, files: FILES, rootFolders: [], capabilities: CAPS_NONE },
+      global: { stubs: globalStubs },
+    })
+    const fileRows = w.findAll('[draggable="true"]')
+    expect(fileRows.length).toBe(0)
+  })
+})

frontend/src/components/ui/AppIcon.vue

@@ -60,6 +60,8 @@ const ICON_PATHS = {
   pencilEdit:        'M15.232 5.232l3.536 3.536m-2.036-5.036a2.5 2.5 0 113.536 3.536L6.5 21.036H3v-3.572L16.732 3.732z',
   lightBulb:         'M9.663 17h4.673M12 3v1m6.364 1.636l-.707.707M21 12h-1M4 12H3m3.343-5.657l-.707-.707m2.828 9.9a5 5 0 117.072 0l-.548.547A3.374 3.374 0 0014 18.469V19a2 2 0 11-4 0v-.531c0-.895-.356-1.754-.988-2.386l-.548-.547z',
   search:            'M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0',
+  info:              'M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z',
+  clock:             'M12 8v4l3 3m6-3a9 9 0 11-18 0 9 9 0 0118 0z',
   dots:              'M12 5v.01M12 12v.01M12 19v.01M12 6a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2z',
   cog: [
     'M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z',