diff --git a/frontend/src/components/ScanProgress.tsx b/frontend/src/components/ScanProgress.tsx
index b3f7991..3aa8434 100644
--- a/frontend/src/components/ScanProgress.tsx
+++ b/frontend/src/components/ScanProgress.tsx
@@ -1,6 +1,6 @@
-import { useEffect, useState } from 'react'
+import { useEffect, useRef, useState } from 'react'
 import { FolderOpen, Loader2, Check, AlertCircle, X } from 'lucide-react'
-import { useQuery } from '@tanstack/react-query'
+import { useQuery, useQueryClient } from '@tanstack/react-query'
 import { library } from '../services/api'
 import clsx from 'clsx'
 
@@ -15,6 +15,8 @@ interface ScanStatus {
 export function ScanProgress() {
   const [isVisible, setIsVisible] = useState(false)
   const [isMinimized, setIsMinimized] = useState(false)
+  const queryClient = useQueryClient()
+  const wasScanningRef = useRef(false)
 
   // Poll scan status every 2 seconds when scanning
   const { data: scanStatus } = useQuery<ScanStatus>({
@@ -31,18 +33,34 @@ export function ScanProgress() {
   })
 
   useEffect(() => {
-    if (scanStatus?.is_scanning) {
+    const isScanning = scanStatus?.is_scanning ?? false
+
+    if (isScanning) {
       setIsVisible(true)
       setIsMinimized(false)
-    } else if (isVisible && !scanStatus?.is_scanning && (scanStatus?.processed_files ?? 0) > 0) {
-      // Keep showing for 3 seconds after scan completes
-      setTimeout(() => {
-        if (!scanStatus?.is_scanning) {
-          setIsVisible(false)
-        }
-      }, 3000)
+      wasScanningRef.current = true
+    } else if (wasScanningRef.current) {
+      // Just transitioned from scanning → done. THIS is the right moment
+      // to invalidate caches that might have new data: the photos query
+      // (new files indexed), the folder tree (new folders walked), the
+      // heap counts (in case a heap photo got reattached).
+      wasScanningRef.current = false
+      queryClient.invalidateQueries({ queryKey: ['photos'] })
+      queryClient.invalidateQueries({ queryKey: ['folders'] })
+      queryClient.invalidateQueries({ queryKey: ['folders', 'tree'] })
+      queryClient.invalidateQueries({ queryKey: ['heaps'] })
+      queryClient.invalidateQueries({ queryKey: ['tags'] })
+
+      if (isVisible && (scanStatus?.processed_files ?? 0) > 0) {
+        // Keep showing for 3 seconds after scan completes
+        setTimeout(() => {
+          if (!scanStatus?.is_scanning) {
+            setIsVisible(false)
+          }
+        }, 3000)
+      }
     }
-  }, [scanStatus?.is_scanning, scanStatus?.processed_files, isVisible])
+  }, [scanStatus?.is_scanning, scanStatus?.processed_files, isVisible, queryClient])
 
   if (!isVisible || !scanStatus) return null
 
diff --git a/frontend/src/components/layout/LeftSidebar.tsx b/frontend/src/components/layout/LeftSidebar.tsx
index 893c37c..ab24f15 100644
--- a/frontend/src/components/layout/LeftSidebar.tsx
+++ b/frontend/src/components/layout/LeftSidebar.tsx
@@ -305,7 +305,14 @@ export function LeftSidebar() {
           onClick={() => {
             if (renamingId === item.id) return
             setSelectedItem(item.id)
-            if (hasChildren) {
+            // Folder rows are always filterable, parent or leaf — clicking
+            // anywhere on the row applies the filter and the chevron
+            // (separate button below) handles expansion. Other group
+            // headers (Library, Folders) just toggle expansion since
+            // they have no associated filter.
+            if (item.id.startsWith('folder-')) {
+              applyLibraryNode(item.id)
+            } else if (hasChildren) {
               toggleExpanded(item.id)
             } else {
               applyLibraryNode(item.id)