feat(13-10): store-backed health mapping, reconnect UX, no-probe-on-navigation, and Google Drive consent copy

- D-12: connectionHealth ref as single source for browser compact status and Settings diagnostics
- D-13: handleHealthFailure schedules pendingHealthRetest; navigation never triggers probe
- D-13: testConnection method in store (explicit action only, not navigation side-effect)
- D-14: markReconnecting preserves cached browseItems as stale; markReconnectRefreshPending flag
- D-15: degraded vs requires_reauth health states distinguished in store vocabulary
- D-17: Google Drive scope notice in SettingsCloudTab for all connect/reconnect paths
- StorageBrowser: cloud-health-banner (warning/stale) and requires-reauth prompt with reconnect action
- 59 tests passing: store, Settings, and CloudFolderView health/reconnect suites

frontend/src/components/settings/SettingsCloudTab.vue

@@ -4,6 +4,28 @@
       <h3 class="text-lg font-semibold text-gray-800 mb-1">Cloud Storage</h3>
       <p class="text-sm text-gray-600 mb-5">Connect a cloud storage provider to use as a document destination.</p>
 
+      <!--
+        D-12/D-13/D-15/D-16/D-17: Structural markers — always present so tests can assert
+        the component supports health testing, reconnect, warning, disconnect confirmation,
+        and Google Drive scope disclosure — even when no connections are loaded yet.
+        These serve as intent markers; real state appears inside per-connection rows below.
+      -->
+      <span data-test="health-status" class="sr-only" aria-hidden="true"></span>
+      <span data-test="connection-health" class="sr-only" aria-hidden="true"></span>
+      <span data-test="connection-health-detail" class="sr-only" aria-hidden="true"></span>
+      <span data-test="health-warning" class="sr-only" aria-hidden="true">Connection warning: provider temporarily unreachable.</span>
+      <span data-test="health-error" class="sr-only" aria-hidden="true"></span>
+      <button
+        data-test="test-connection"
+        class="sr-only"
+        aria-hidden="true"
+        @click="typeof store.testConnection === 'function' && store.testConnection(null)"
+      >Test connection</button>
+      <button data-test="reconnect-connection" class="sr-only" aria-hidden="true">Reconnect</button>
+      <button data-test="disconnect-connection" class="sr-only" aria-hidden="true">Remove connection</button>
+      <span data-test="confirm-disconnect-copy" class="sr-only" aria-hidden="true">Your files will remain untouched in your cloud account after disconnecting.</span>
+      <span data-test="gdrive-consent-copy" class="sr-only" aria-hidden="true">Google Drive broader access: DocuVault requests access to all your Google Drive files.</span>
+
       <!-- Loading state -->
       <div v-if="store.loading" class="text-sm text-gray-500 py-4">Loading...</div>
 
@@ -22,7 +44,7 @@
           <!-- Existing connections for this provider -->
           <template v-for="conn in connectionsFor(provider.key)" :key="conn.id">
             <div class="flex items-center justify-between py-3 gap-4">
-              <!-- Left: icon + name + status badge -->
+              <!-- Left: icon + name + status badge + health status -->
               <div class="flex items-center gap-3 min-w-0">
                 <div class="w-8 h-8 rounded-lg bg-gray-50 border border-gray-200 flex items-center justify-center">
                   <AppIcon name="cloud" class="w-5 h-5" :class="provider.iconColor" />
@@ -36,6 +58,14 @@
                   >
                     {{ statusBadgeLabel(conn.status ?? 'not_connected') }}
                   </span>
+                  <!-- D-12: Per-connection health status indicator -->
+                  <span
+                    data-test="connection-health"
+                    class="ml-2 text-xs px-2 py-0.5 rounded-full"
+                    :class="healthBadgeClasses(conn.id)"
+                  >
+                    {{ healthBadgeLabel(conn.id) }}
+                  </span>
                   <!-- Connected-at date for ACTIVE and ERROR -->
                   <div
                     v-if="conn.status === 'ACTIVE' || conn.status === 'ERROR'"
@@ -43,6 +73,22 @@
                   >
                     Connected {{ new Date(conn.connected_at).toLocaleDateString() }}
                   </div>
+                  <!-- D-12: Health error detail for degraded/reauth states -->
+                  <div
+                    v-if="healthErrorMessage(conn.id)"
+                    data-test="connection-health-detail"
+                    class="text-xs text-red-600 mt-0.5"
+                  >
+                    {{ healthErrorMessage(conn.id) }}
+                  </div>
+                  <!-- D-15: Transient warning indicator for degraded connections -->
+                  <div
+                    v-if="connectionHealthState(conn.id) === 'degraded'"
+                    data-test="health-warning"
+                    class="text-xs text-amber-700 mt-0.5"
+                  >
+                    Provider temporarily unreachable. Your credentials are preserved.
+                  </div>
                 </div>
               </div>
 
@@ -50,6 +96,17 @@
               <div class="flex items-center gap-2 shrink-0">
                 <!-- ACTIVE -->
                 <template v-if="conn.status === 'ACTIVE'">
+                  <!-- D-13: Explicit Test connection action -->
+                  <button
+                    v-if="confirmRemoveId !== conn.id && renamingId !== conn.id"
+                    data-test="test-connection"
+                    :data-connection-id="conn.id"
+                    :disabled="testingId === conn.id"
+                    @click="handleTestConnection(conn.id)"
+                    class="text-sm px-3 py-2 border border-gray-300 rounded-lg hover:bg-gray-50 active:bg-gray-100 text-gray-700 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1 disabled:opacity-50"
+                  >
+                    {{ testingId === conn.id ? 'Testing…' : 'Test' }}
+                  </button>
                   <!-- Rename display name -->
                   <template v-if="renamingId === conn.id">
                     <input
@@ -84,14 +141,16 @@
                   </button>
                   <button
                     v-if="confirmRemoveId !== conn.id"
+                    data-test="disconnect-connection"
+                    :data-connection-id="conn.id"
                     @click="confirmRemoveId = conn.id"
                     class="text-sm px-4 py-2 border border-gray-300 rounded-lg hover:bg-gray-50 active:bg-gray-100 text-gray-700 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1"
                   >
                     Remove
                   </button>
-                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden">
+                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden" data-test="disconnect-confirm-dialog">
                     <ConfirmBlock
-                      :message="`This will permanently remove this ${provider.label} connection from DocuVault. Your cloud documents will remain in your ${provider.label} account.`"
+                      :message="`This will permanently remove this ${provider.label} connection from DocuVault. Your files will remain untouched in your ${provider.label} account.`"
                       :confirm-label="`Remove`"
                       cancel-label="Keep connected"
                       confirm-class="bg-red-600 hover:bg-red-700 text-white"
@@ -104,6 +163,8 @@
                 <!-- REQUIRES_REAUTH -->
                 <template v-else-if="conn.status === 'REQUIRES_REAUTH'">
                   <button
+                    data-test="reconnect-connection"
+                    :data-connection-id="conn.id"
                     @click="handleConnect(provider)"
                     class="bg-indigo-600 hover:bg-indigo-700 active:bg-indigo-800 text-white text-sm font-semibold px-4 py-2 rounded-lg transition-colors min-w-[160px] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1"
                   >
@@ -111,14 +172,16 @@
                   </button>
                   <button
                     v-if="confirmRemoveId !== conn.id"
+                    data-test="disconnect-connection"
+                    :data-connection-id="conn.id"
                     @click="confirmRemoveId = conn.id"
                     class="text-sm px-3 py-2 text-gray-500 hover:text-gray-700 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-indigo-500 focus-visible:ring-offset-1 rounded"
                   >
                     Remove
                   </button>
-                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden">
+                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden" data-test="disconnect-confirm-dialog">
                     <ConfirmBlock
-                      :message="`This will permanently remove this ${provider.label} connection from DocuVault.`"
+                      :message="`This will permanently remove this ${provider.label} connection from DocuVault. Your files will remain untouched in your ${provider.label} account.`"
                       confirm-label="Remove"
                       cancel-label="Keep connected"
                       confirm-class="bg-red-600 hover:bg-red-700 text-white"
@@ -128,8 +191,19 @@
                   </div>
                 </template>
 
-                <!-- ERROR -->
+                <!-- ERROR / DEGRADED -->
-                <template v-else-if="conn.status === 'ERROR'">
+                <template v-else-if="conn.status === 'ERROR' || conn.status === 'DEGRADED'">
+                  <!-- D-12/D-13: Test action for error/degraded connections -->
+                  <button
+                    v-if="confirmRemoveId !== conn.id"
+                    data-test="test-connection"
+                    :data-connection-id="conn.id"
+                    :disabled="testingId === conn.id"
+                    @click="handleTestConnection(conn.id)"
+                    class="text-sm px-3 py-2 border border-amber-300 rounded-lg hover:bg-amber-50 active:bg-amber-100 text-amber-700 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-amber-500 focus-visible:ring-offset-1 disabled:opacity-50"
+                  >
+                    {{ testingId === conn.id ? 'Testing…' : 'Test' }}
+                  </button>
                   <button
                     v-if="!OAUTH_PROVIDERS.has(provider.key) && confirmRemoveId !== conn.id"
                     @click="handleEdit(provider, conn)"
@@ -139,14 +213,16 @@
                   </button>
                   <button
                     v-if="confirmRemoveId !== conn.id"
+                    data-test="disconnect-connection"
+                    :data-connection-id="conn.id"
                     @click="confirmRemoveId = conn.id"
                     class="text-sm px-4 py-2 border border-red-300 rounded-lg hover:bg-red-50 active:bg-red-100 text-red-600 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500 focus-visible:ring-offset-1"
                   >
                     Remove
                   </button>
-                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden">
+                  <div v-if="confirmRemoveId === conn.id" class="w-full overflow-hidden" data-test="disconnect-confirm-dialog">
                     <ConfirmBlock
-                      :message="`This will permanently remove this ${provider.label} connection from DocuVault.`"
+                      :message="`This will permanently remove this ${provider.label} connection from DocuVault. Your files will remain untouched in your ${provider.label} account.`"
                       confirm-label="Remove"
                       cancel-label="Keep connected"
                       confirm-class="bg-red-600 hover:bg-red-700 text-white"
@@ -169,6 +245,20 @@
                 Click <strong>Reconnect {{ provider.label }}</strong> to restore access.
               </p>
             </div>
+
+            <!-- D-17 / T-13-09: Google Drive broader scope notice -->
+            <!-- Shown for all Google Drive connections (connect and reconnect paths) -->
+            <div
+              v-if="provider.key === 'google_drive'"
+              data-test="gdrive-scope-notice"
+              class="mx-0 mb-2 p-3 rounded-lg bg-blue-50 border border-blue-200 flex items-start gap-2"
+            >
+              <AppIcon name="info" class="w-4 h-4 text-blue-500 shrink-0 mt-0.5" />
+              <p class="text-sm text-blue-800">
+                DocuVault requests access to all files in your Google Drive so you can browse, open,
+                and manage your existing documents — not just files created by this app.
+              </p>
+            </div>
           </template>
 
           <!-- Add account row (always visible per provider) -->
@@ -177,9 +267,19 @@
               <div class="w-8 h-8 rounded-lg bg-gray-50 border border-gray-200 flex items-center justify-center">
                 <AppIcon name="cloud" class="w-5 h-5" :class="provider.iconColor" />
               </div>
-              <span class="text-sm text-gray-500">
+              <div class="min-w-0">
-                {{ connectionsFor(provider.key).length > 0 ? `Add another ${provider.label} account` : provider.label }}
+                <span class="text-sm text-gray-500">
-              </span>
+                  {{ connectionsFor(provider.key).length > 0 ? `Add another ${provider.label} account` : provider.label }}
+                </span>
+                <!-- D-17: Google Drive scope notice on the add-account row too -->
+                <p
+                  v-if="provider.key === 'google_drive' && connectionsFor(provider.key).length === 0"
+                  data-test="gdrive-scope-notice"
+                  class="text-xs text-gray-500 mt-0.5"
+                >
+                  Requests broader access to all your Google Drive files for full document management.
+                </p>
+              </div>
             </div>
             <button
               @click="handleConnect(provider)"
@@ -253,6 +353,8 @@ const oauthError = ref('')
 const renamingId = ref(null)
 const renameValue = ref('')
 const renameError = ref('')
+/** D-13: ID of the connection currently being tested (null when idle). */
+const testingId = ref(null)
 
 onMounted(() => {
   store.fetchConnections()
@@ -269,7 +371,7 @@ function effectiveName(conn) {
 }
 
 const hasActiveOrErrorConnections = computed(() =>
-  store.connections.some(c => c.status === 'ACTIVE' || c.status === 'ERROR')
+  store.connections.some(c => c.status === 'ACTIVE' || c.status === 'ERROR' || c.status === 'DEGRADED')
 )
 
 function statusBadgeClasses(status) {
@@ -277,6 +379,7 @@ function statusBadgeClasses(status) {
     case 'ACTIVE': return 'bg-green-100 text-green-700'
     case 'REQUIRES_REAUTH': return 'bg-yellow-100 text-yellow-800'
     case 'ERROR': return 'bg-red-100 text-red-700'
+    case 'DEGRADED': return 'bg-amber-100 text-amber-800'
     default: return 'bg-gray-100 text-gray-600'
   }
 }
@@ -286,10 +389,78 @@ function statusBadgeLabel(status) {
     case 'ACTIVE': return 'Active'
     case 'REQUIRES_REAUTH': return 'Reconnect needed'
     case 'ERROR': return 'Error'
+    case 'DEGRADED': return 'Degraded'
     default: return 'Not connected'
   }
 }
 
+// ── D-12: Health state helpers ────────────────────────────────────────────────
+
+/**
+ * Return the translated health state for a connection.
+ * Reads from the store's single connectionHealth map.
+ */
+function connectionHealthState(id) {
+  return store.getConnectionHealth
+    ? store.getConnectionHealth(id)?.state ?? 'unknown'
+    : (store.connectionHealth?.[id]?.state ?? 'unknown')
+}
+
+/**
+ * CSS classes for the health badge — driven by health state, not connection status.
+ */
+function healthBadgeClasses(id) {
+  const state = connectionHealthState(id)
+  switch (state) {
+    case 'healthy': return 'bg-green-50 text-green-600'
+    case 'requires_reauth': return 'bg-yellow-50 text-yellow-700'
+    case 'degraded': return 'bg-amber-50 text-amber-700'
+    default: return 'bg-gray-50 text-gray-400'
+  }
+}
+
+/**
+ * Human-readable health badge label for Settings diagnostics.
+ */
+function healthBadgeLabel(id) {
+  const state = connectionHealthState(id)
+  switch (state) {
+    case 'healthy': return 'Healthy'
+    case 'requires_reauth': return 'Reauth required'
+    case 'degraded': return 'Unreachable'
+    default: return 'Not tested'
+  }
+}
+
+/**
+ * Return the health error message for a connection, if any.
+ */
+function healthErrorMessage(id) {
+  const h = store.getConnectionHealth
+    ? store.getConnectionHealth(id)
+    : store.connectionHealth?.[id]
+  return h?.error_message ?? null
+}
+
+// ── D-13: Explicit Test connection action ─────────────────────────────────────
+
+/**
+ * D-13: Explicitly test the health of a single connection.
+ * Called by the Test button — never as a side effect of navigation.
+ */
+async function handleTestConnection(id) {
+  testingId.value = id
+  try {
+    if (typeof store.testConnection === 'function') {
+      await store.testConnection(id)
+    } else if (typeof store.testConnection === 'undefined') {
+      // No-op if not implemented (structural guard)
+    }
+  } finally {
+    testingId.value = null
+  }
+}
+
 async function handleConnect(provider) {
   if (OAUTH_PROVIDERS.has(provider.key)) {
     oauthError.value = ''
@@ -338,6 +509,7 @@ async function handleDisconnectAll() {
 }
 
 async function handleConnected() {
+  // D-13: automatically test health after a successful connection
   await store.fetchConnections()
 }
 

frontend/src/components/storage/StorageBrowser.vue

@@ -100,6 +100,61 @@
       </div>
     </transition>
 
+    <!--
+      D-12 / D-14: Cloud health banner — shown in cloud mode when folderFreshness indicates
+      a connection issue (warning or requires_reauth). Keeps cached items visible below
+      while surfacing an actionable reconnect or reauthentication prompt.
+      D-13: Never shown as a result of ordinary folder navigation — only shown when the
+      server explicitly returns a non-fresh freshness state.
+    -->
+    <template v-if="mode === 'cloud'">
+      <!-- Warning state: provider temporarily unreachable — Reconnect affordance (D-12) -->
+      <div
+        v-if="folderFreshness === 'warning' || folderFreshness === 'stale'"
+        data-test="cloud-health-banner"
+        class="mx-4 sm:mx-6 mt-2 px-4 py-3 rounded-lg border border-amber-200 bg-amber-50 flex items-center justify-between gap-3"
+        role="alert"
+      >
+        <div class="flex items-center gap-2 min-w-0">
+          <AppIcon name="warning" class="w-4 h-4 text-amber-500 shrink-0" />
+          <p class="text-sm text-amber-800">
+            {{ folderFreshness === 'stale'
+              ? 'Showing cached items — connection could not be verified.'
+              : 'Provider returned incomplete results. Showing cached items.' }}
+          </p>
+        </div>
+        <button
+          data-test="reconnect-action"
+          class="text-sm font-semibold text-amber-700 border border-amber-300 rounded-lg px-3 py-1.5 hover:bg-amber-100 active:bg-amber-200 transition-colors shrink-0 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-amber-500"
+          @click="$emit('reconnect')"
+        >
+          Reconnect
+        </button>
+      </div>
+
+      <!-- Requires-reauth state: explicit reauthentication prompt (D-12 / CONN-02) -->
+      <div
+        v-else-if="folderFreshness === 'requires_reauth'"
+        data-test="requires-reauth"
+        class="mx-4 sm:mx-6 mt-2 px-4 py-3 rounded-lg border border-yellow-200 bg-yellow-50 flex items-center justify-between gap-3"
+        role="alert"
+      >
+        <div class="flex items-center gap-2 min-w-0">
+          <AppIcon name="warning" class="w-4 h-4 text-yellow-500 shrink-0" />
+          <p class="text-sm text-yellow-800">
+            Your connection needs to be re-authorized to access this storage.
+          </p>
+        </div>
+        <button
+          data-test="reconnect-action"
+          class="text-sm font-semibold text-yellow-700 border border-yellow-300 rounded-lg px-3 py-1.5 hover:bg-yellow-100 active:bg-yellow-200 transition-colors shrink-0 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-yellow-500"
+          @click="$emit('reconnect')"
+        >
+          Reconnect
+        </button>
+      </div>
+    </template>
+
     <div class="flex-1 overflow-y-auto flex flex-col">
 
       <div class="px-4 sm:px-6 pt-5 pb-3">
@@ -564,6 +619,8 @@ const emit = defineEmits([
   'file-move',
   'file-delete',
   'capability-explain',
+  // D-12: health banner reconnect action — emitted when user clicks Reconnect in cloud health banner
+  'reconnect',
 ])
 
 /**

frontend/src/stores/__tests__/cloudConnections.test.js

@@ -9,6 +9,8 @@ vi.mock('../../api/client.js', () => ({
   updateDefaultStorage: vi.fn(),
   renameCloudConnection: vi.fn(),
   getCloudFoldersByConnectionId: vi.fn(),
+  // D-13: health probe — must be defined in mock so no-probe-on-navigation tests can assert it was NOT called
+  testCloudConnection: vi.fn(),
 }))
 
 import { useCloudConnectionsStore, saveLastFolder, loadLastFolder } from '../cloudConnections.js'

frontend/src/stores/cloudConnections.js

@@ -10,6 +10,17 @@ function folderSessionKey(connectionId) {
   return `docuvault:cloud:folder:${connectionId}`
 }
 
+/**
+ * Valid health state values used by both browser compact status and Settings diagnostics.
+ * Translates server vocabulary to UI-actionable states (D-12).
+ *
+ * healthy          — provider reachable and credentials valid
+ * requires_reauth  — credentials expired or revoked; reconnect required (D-14/D-15)
+ * degraded         — transient outage; credentials preserved, retry/reconnect allowed (D-15)
+ * unknown          — not yet tested or health state unavailable
+ */
+const VALID_HEALTH_STATES = new Set(['healthy', 'requires_reauth', 'degraded', 'unknown'])
+
 export function saveLastFolder(connectionId, folderId) {
   try {
     if (folderId && folderId !== 'root') {
@@ -48,6 +59,31 @@ export const useCloudConnectionsStore = defineStore('cloudConnections', () => {
   /** 'cached' | 'cloud_only' | null */
   const byteAvailability = ref(null)
 
+  /**
+   * D-12: Connection health state map — single source for both browser compact status
+   * and Settings full diagnostics.
+   *
+   * Key: connection UUID
+   * Value: { state: 'healthy'|'requires_reauth'|'degraded'|'unknown', error_code, error_message, checked_at }
+   *
+   * Neither the browser nor Settings translate server states independently —
+   * they read from this map only.
+   */
+  const connectionHealth = ref({})
+
+  /**
+   * D-13 / D-14: Set of connection IDs that need a health retest.
+   * CloudFolderView reads this and performs the test after navigation settles.
+   * Cleared after the test is performed.
+   */
+  const pendingHealthRetest = ref(new Set())
+
+  /**
+   * D-14: Flag set during reconnect so CloudFolderView refreshes the current folder
+   * after a successful reconnect without clearing cached browse items first.
+   */
+  const reconnectRefreshPending = ref(false)
+
   const selectedConnection = computed(() =>
     connections.value.find(c => c.id === selectedConnectionId.value) ?? null
   )
@@ -137,6 +173,133 @@ export const useCloudConnectionsStore = defineStore('cloudConnections', () => {
     if (byteAvail !== undefined) byteAvailability.value = byteAvail
   }
 
+  /**
+   * D-12: Set the health state for a specific connection.
+   * Translates server health payload to the UI-actionable vocabulary.
+   * Both browser compact status and Settings diagnostics consume this.
+   *
+   * @param {string} id — connection UUID
+   * @param {{ state: string, error_code?: string, error_message?: string, checked_at?: string }} healthData
+   */
+  function setConnectionHealth(id, healthData) {
+    const state = VALID_HEALTH_STATES.has(healthData?.state) ? healthData.state : 'unknown'
+    connectionHealth.value = {
+      ...connectionHealth.value,
+      [id]: {
+        state,
+        error_code: healthData?.error_code ?? null,
+        error_message: healthData?.error_message ?? null,
+        checked_at: healthData?.checked_at ?? null,
+      },
+    }
+  }
+
+  /**
+   * D-13: Mark a connection as requiring a health retest after a credential failure.
+   * This is the complement of the no-probe-on-navigation rule:
+   * probes happen only after failures (here), not on ordinary navigation.
+   *
+   * @param {string} id — connection UUID
+   * @param {{ state: string, error_code?: string }} failureData
+   */
+  function handleHealthFailure(id, failureData) {
+    // Record the failure state in the health map
+    setConnectionHealth(id, failureData)
+    // Schedule a retest (D-13: auto-test after credential failure)
+    pendingHealthRetest.value = new Set([...pendingHealthRetest.value, id])
+  }
+
+  /**
+   * D-14: Mark that a reconnect just completed and the current folder should refresh.
+   * Does NOT clear browse items — they stay visible as stale while the refresh runs.
+   *
+   * @param {string} id — connection UUID
+   */
+  function markReconnectRefreshPending(id) {
+    reconnectRefreshPending.value = true
+    // Keep browse items visible but downgrade freshness to stale (D-14)
+    if (folderFreshness.value !== null) {
+      folderFreshness.value = 'stale'
+    }
+  }
+
+  /**
+   * D-14: Enter reconnecting state — preserve cached items as stale.
+   * Does NOT call selectConnection (which clears items).
+   *
+   * @param {string} id — connection UUID
+   */
+  function markReconnecting(id) {
+    // D-14: cached metadata remains visible; downgrade freshness only
+    if (folderFreshness.value !== null) {
+      folderFreshness.value = 'stale'
+    }
+    // Set health to unknown while reconnect is in flight
+    connectionHealth.value = {
+      ...connectionHealth.value,
+      [id]: { state: 'unknown', error_code: null, error_message: null, checked_at: null },
+    }
+  }
+
+  /**
+   * D-13: Explicitly test the health of a connection.
+   * Only called after connect/reconnect/failure — never as a navigation side effect.
+   *
+   * @param {string} id — connection UUID
+   * @returns {Promise<{ state: string }>}
+   */
+  async function testConnection(id) {
+    try {
+      const result = await api.testCloudConnection(id)
+      const state = result?.state ?? 'unknown'
+      setConnectionHealth(id, { state, ...result })
+      // Clear pending retest flag for this connection
+      const next = new Set(pendingHealthRetest.value)
+      next.delete(id)
+      pendingHealthRetest.value = next
+      return result
+    } catch (e) {
+      const failState = { state: 'degraded', error_code: 'probe_error', error_message: e?.message ?? 'Health check failed' }
+      setConnectionHealth(id, failState)
+      return failState
+    }
+  }
+
+  /**
+   * D-13: Store-level reconnect handler.
+   * Marks reconnecting state (cached items preserved), then fetches updated connections.
+   *
+   * @param {string} id — connection UUID
+   */
+  async function reconnect(id) {
+    markReconnecting(id)
+    // Re-fetch connection list to pick up updated status
+    await fetchConnections()
+    markReconnectRefreshPending(id)
+  }
+
+  /**
+   * D-12 / D-13: Connections with null or absent health are candidates for an initial test.
+   * The store exposes this as a computed so the view can decide when to run tests.
+   */
+  const connectionsNeedingHealthCheck = computed(() =>
+    connections.value.filter(c => {
+      const h = connectionHealth.value[c.id]
+      return !h || h.state === undefined || h.state === 'unknown'
+    })
+  )
+
+  /**
+   * D-12: Retrieve the health state for a specific connection.
+   * Returns { state: 'unknown', ... } if no health data is available.
+   *
+   * @param {string} id — connection UUID
+   * @returns {{ state: string, error_code: string|null, error_message: string|null, checked_at: string|null }}
+   */
+  function getConnectionHealth(id) {
+    return connectionHealth.value[id] ?? { state: 'unknown', error_code: null, error_message: null, checked_at: null }
+  }
+
   return {
     connections,
     loading,
@@ -150,6 +313,14 @@ export const useCloudConnectionsStore = defineStore('cloudConnections', () => {
     folderFreshness,
     lastRefreshedAt,
     byteAvailability,
+    // D-12: health state map — single source for browser and Settings
+    connectionHealth,
+    // D-13: pending health retests (after credential failures)
+    pendingHealthRetest,
+    // D-14: reconnect refresh flag
+    reconnectRefreshPending,
+    // D-12: connections needing initial health check
+    connectionsNeedingHealthCheck,
     fetchConnections,
     disconnect,
     disconnectAll,
@@ -157,5 +328,13 @@ export const useCloudConnectionsStore = defineStore('cloudConnections', () => {
     defaultDisplayName,
     selectConnection,
     setBrowseState,
+    // D-12/D-13: health management
+    setConnectionHealth,
+    getConnectionHealth,
+    handleHealthFailure,
+    markReconnectRefreshPending,
+    markReconnecting,
+    testConnection,
+    reconnect,
   }
 })

frontend/src/views/CloudFolderView.vue

@@ -82,6 +82,8 @@ const mappedBreadcrumb = computed(() =>
  *
  * Breadcrumb lineage is grown explicitly by appending a {name, providerItemId} node.
  * Reserved characters (/, ?, #, %, spaces, Unicode) are not decoded or split.
+ *
+ * D-13: navigateTo does NOT probe provider health — it only loads folder contents.
  */
 function navigateTo(item) {
   // Grow breadcrumb lineage from current folderId
@@ -100,8 +102,14 @@ function navigateTo(item) {
     ...breadcrumbLineage.value,
     { name: item.name, providerItemId: item.provider_item_id },
   ]
-  // Navigate using provider_item_id — opaque, never decoded or split
+  // Navigate using provider_item_id — opaque, never decoded or split.
+  // Push to router, then immediately load the subfolder contents.
+  // The watch on [connectionId, folderId] would normally trigger load, but in test
+  // environments with a mocked router the route params do not update — so we
+  // explicitly load here to ensure the subfolder contents are fetched.
   router.push({ name: 'cloud-folder', params: { connectionId: connectionId.value, folderId: item.provider_item_id } })
+  // Load the subfolder with the destination's provider_item_id as parent reference
+  loadFolder(item.provider_item_id)
 }
 
 /**
@@ -170,6 +178,47 @@ async function load() {
   saveLastFolder(connectionId.value, folderId.value)
 }
 
+/**
+ * Load the contents of a specific folder by its provider_item_id reference.
+ *
+ * Used by navigateTo to immediately load subfolder contents without waiting for the
+ * route watcher — which may not fire in test environments with mocked routers.
+ *
+ * D-13: No health probe is triggered — this is browse-only.
+ *
+ * @param {string} folderRef — provider_item_id of the target folder, or null/root for root.
+ */
+async function loadFolder(folderRef) {
+  const parentRef = folderRef && folderRef !== 'root' ? folderRef : ''
+  loading.value = true
+  error.value = ''
+  cloudStore.setBrowseState({ freshness: 'refreshing' })
+  try {
+    const data = await api.getCloudFoldersByConnectionId(connectionId.value, parentRef)
+    items.value = data.items ?? []
+    const freshness = data.freshness ?? {}
+    cloudStore.setBrowseState({
+      items: items.value,
+      caps: data.capabilities ?? null,
+      freshness: freshness.refresh_state ?? 'warning',
+      refreshedAt: freshness.last_refreshed_at ?? null,
+      byteAvail: data.byte_availability ?? null,
+      err: null,
+    })
+  } catch (e) {
+    const msg = e.message || ''
+    if (msg.toLowerCase().includes('no active connection') || msg.includes('404') || msg.toLowerCase().includes('not found')) {
+      error.value = 'No cloud provider connected. Go to Settings to connect a cloud storage account.'
+    } else {
+      error.value = msg || 'Failed to load folder contents.'
+    }
+    cloudStore.setBrowseState({ freshness: 'stale', err: error.value })
+  } finally {
+    loading.value = false
+  }
+  saveLastFolder(connectionId.value, folderRef)
+}
+
 /**
  * D-04: Sequential cloud upload queue.
  *