feat(ui): Cloud page renders from cache — per-peer incremental fan-in, live FIPS/Tor badges, per-path folder cache

Part B3 of docs/FIPS-UPTIME-AND-UI-STATE-PLAN.md — the worst
fetch-on-every-navigation offender converted to the cached-resource layer:

- section counts / peer nodes / my files / paid items are cached resources:
  revisits paint instantly, refresh happens behind the content
  (sticky-ready), errors keep last-known data
- peer files: per-peer cached browse entries replace the all-or-nothing
  Promise.allSettled — each peer's rows render the moment it answers, with
  "still fetching from N peers" + unreachable counts; browse-peer runs
  with maxRetries:1 so one dead peer costs its timeout once, not ×3
- peer cards get a live transport badge (FIPS green / Tor amber, with
  measured latency) from the transport field the browse response already
  carried — the per-peer FIPS-uptime view, for free
- cloud store: per-path listing cache with stale-while-revalidate
  navigate() and a last-wins guard; CloudFolder no longer reset()s the
  store on every folder entry (that wipe forced a spinner each time)

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

neode-ui/src/stores/cloud.ts

@@ -8,6 +8,11 @@ export const useCloudStore = defineStore('cloud', () => {
   const loading = ref(false)
   const error = ref<string | null>(null)
   const authenticated = ref(false)
+  // Per-path listing cache: re-entering a folder paints the last listing
+  // immediately (no spinner) while the fresh listing loads behind it.
+  const pathCache = new Map<string, FileBrowserItem[]>()
+  // Last-wins guard for overlapping navigations (fast folder hopping).
+  let navSeq = 0
 
   const breadcrumbs = computed(() => {
     const parts = currentPath.value.split('/').filter(Boolean)
@@ -36,7 +41,22 @@ export const useCloudStore = defineStore('cloud', () => {
   }
 
   async function navigate(path: string): Promise<void> {
-    loading.value = true
+    const seq = ++navSeq
+    const apply = (p: string, result: FileBrowserItem[]) => {
+      pathCache.set(p, result)
+      if (seq !== navSeq) return // a newer navigation superseded this one
+      items.value = result
+      currentPath.value = p
+    }
+    // Stale-while-revalidate: show the cached listing for this path
+    // immediately (no spinner), then refresh it underneath.
+    const cached = pathCache.get(path)
+    if (cached) {
+      items.value = cached
+      currentPath.value = path
+    } else {
+      loading.value = true
+    }
     error.value = null
     try {
       if (!authenticated.value) {
@@ -47,9 +67,7 @@ export const useCloudStore = defineStore('cloud', () => {
         }
       }
       try {
-        const result = await fileBrowserClient.listDirectory(path)
-        items.value = result
-        currentPath.value = path
+        apply(path, await fileBrowserClient.listDirectory(path))
       } catch {
         // Directory may not exist — try to create it, then retry
         if (path !== '/') {
@@ -57,23 +75,20 @@ export const useCloudStore = defineStore('cloud', () => {
             const parentPath = path.substring(0, path.lastIndexOf('/')) || '/'
             const dirName = path.substring(path.lastIndexOf('/') + 1)
             await fileBrowserClient.createFolder(parentPath, dirName)
-            const result = await fileBrowserClient.listDirectory(path)
-            items.value = result
-            currentPath.value = path
+            apply(path, await fileBrowserClient.listDirectory(path))
           } catch {
             // Fall back to root
-            const result = await fileBrowserClient.listDirectory('/')
-            items.value = result
-            currentPath.value = '/'
+            apply('/', await fileBrowserClient.listDirectory('/'))
           }
         } else {
           throw new Error('Failed to list root directory')
         }
       }
     } catch (e) {
-      error.value = e instanceof Error ? e.message : 'Failed to load files'
+      // Keep showing the cached listing on a failed revalidate.
+      if (!cached) error.value = e instanceof Error ? e.message : 'Failed to load files'
     } finally {
-      loading.value = false
+      if (seq === navSeq) loading.value = false
     }
   }
 
@@ -112,6 +127,7 @@ export const useCloudStore = defineStore('cloud', () => {
     items.value = []
     loading.value = false
     error.value = null
+    pathCache.clear()
   }
 
   return {