test(12.1-03): add RED tests for server freshness mapping

- cloudConnections: setBrowseState warning/refreshing/fresh states
- cloudConnections: cached items remain during warning
- cloudConnections: selectConnection clears browse state
- cloudConnections: does_not_use_browser_clock_as_refresh_evidence
- CloudFolderView: maps_server_warning_and_last_success
- CloudFolderView: http_200_does_not_imply_fresh
- CloudFolderView: does_not_use_browser_clock_as_refresh_evidence
- CloudFolderView: cached_items_remain_visible_during_warning
3 new failures against unconditional fresh/new Date() behavior

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

@@ -156,3 +156,83 @@ describe('useCloudConnectionsStore', () => {
     expect(stored.startsWith('{')).toBe(false)
   })
 })
+
+// ── Freshness state mapping ──────────────────────────────────────────────────
+
+describe('setBrowseState freshness mapping', () => {
+  it('setBrowseState with freshness=warning sets folderFreshness to "warning"', () => {
+    const store = useCloudConnectionsStore()
+    store.setBrowseState({ freshness: 'warning' })
+    expect(store.folderFreshness).toBe('warning')
+  })
+
+  it('setBrowseState with freshness=refreshing sets folderFreshness to "refreshing"', () => {
+    const store = useCloudConnectionsStore()
+    store.setBrowseState({ freshness: 'refreshing' })
+    expect(store.folderFreshness).toBe('refreshing')
+  })
+
+  it('setBrowseState with freshness=fresh sets folderFreshness to "fresh"', () => {
+    const store = useCloudConnectionsStore()
+    store.setBrowseState({ freshness: 'fresh' })
+    expect(store.folderFreshness).toBe('fresh')
+  })
+
+  it('maps_server_warning_and_last_success: server last_refreshed_at is preserved exactly', () => {
+    const store = useCloudConnectionsStore()
+    const serverTimestamp = '2026-06-15T10:30:00Z'
+    store.setBrowseState({
+      freshness: 'warning',
+      refreshedAt: serverTimestamp,
+    })
+    expect(store.folderFreshness).toBe('warning')
+    expect(store.lastRefreshedAt).toBe(serverTimestamp)
+  })
+
+  it('selectConnection clears cloud browse state without persisting secrets', () => {
+    const store = useCloudConnectionsStore()
+    store.connections = [{ id: 'conn-1', provider: 'google_drive' }]
+    // Set some browse state
+    store.setBrowseState({
+      items: [{ id: 'item-1', name: 'doc.pdf' }],
+      caps: { share: true },
+      freshness: 'fresh',
+      refreshedAt: '2026-06-15T10:30:00Z',
+      byteAvail: 'cached',
+      err: null,
+    })
+    // Select a different connection — should clear state
+    store.selectConnection('conn-1')
+    expect(store.browseItems).toHaveLength(0)
+    expect(store.folderFreshness).toBeNull()
+    expect(store.lastRefreshedAt).toBeNull()
+    expect(store.capabilities).toBeNull()
+    expect(store.byteAvailability).toBeNull()
+    // No tokens or credentials should be present
+    expect(store.browseError).toBeNull()
+  })
+
+  it('does_not_use_browser_clock_as_refresh_evidence: refreshedAt from server, not Date.now', () => {
+    const store = useCloudConnectionsStore()
+    // Store only accepts what is passed explicitly — no implicit Date()
+    const SERVER_TS = '2026-06-10T08:00:00.000Z'
+    store.setBrowseState({ freshness: 'fresh', refreshedAt: SERVER_TS })
+    // lastRefreshedAt must equal exactly what was passed — not a new Date()
+    expect(store.lastRefreshedAt).toBe(SERVER_TS)
+  })
+
+  it('cached_items_remain_visible_during_warning: items not cleared on warning freshness', () => {
+    const store = useCloudConnectionsStore()
+    const cachedItems = [
+      { id: 'item-a', provider_item_id: 'pref-a', name: 'Cached Folder', kind: 'folder' },
+    ]
+    // First, set fresh state with items
+    store.setBrowseState({ items: cachedItems, freshness: 'fresh', refreshedAt: '2026-06-01T00:00:00Z' })
+    expect(store.browseItems).toHaveLength(1)
+    // Now simulate a warning without clearing items (only freshness changes)
+    store.setBrowseState({ freshness: 'warning' })
+    // Items must still be there — warning does not delete cached items
+    expect(store.browseItems).toHaveLength(1)
+    expect(store.browseItems[0].id).toBe('item-a')
+  })
+})