fix: retention starvation + duplicate threshold, perf and UI polish (v0.6.1)

Sources/StorageScope/Stores/FilterStore.swift

@@ -81,6 +81,18 @@ final class FilterStore: ObservableObject {
         didSet { coordinateInvalidate() }
     }
 
+    /// Scanner inclusion threshold for same-size duplicate candidacy, in MB. Default lowered
+    /// from the old fixed 100MB (see `ScanOptionPolicy`) because at 100MB nearly every file
+    /// in a typical folder (photos, PDFs, code, installers under a few dozen MB) never became
+    /// a candidate, so Duplicate Review found almost nothing for most users' real folders.
+    /// 10MB still excludes the long tail of tiny files (source, text, thumbnails) that would
+    /// blow up hashing volume, while catching the common duplicate cases. The verify byte/file
+    /// budget (`ScanOptions.duplicateVerificationByteLimit`/`maxDuplicateVerificationFiles`)
+    /// remains the wall-time safety valve regardless of how low this goes.
+    @Published var duplicateCandidateThresholdMB: Int = 10 {
+        didSet { coordinateInvalidate() }
+    }
+
     /// Set when the user clicks a row on `TypeBreakdownView` — narrows downstream views
     /// (currently `.largestFiles`) to files whose `fileExtension` matches. Cleared on its own
     /// when the user dismisses the corresponding chip, or anytime `query` changes so the user

Sources/StorageScope/Stores/ScanStore.swift

@@ -7,6 +7,11 @@ import os
 final class ScanStore: ObservableObject {
     private static let overviewItemCap = 100
 
+    /// Single source of truth for the ranked-list cap passed to `ScanOptions` below, and
+    /// surfaced read-only via `scanRankedResultsCap` so the Overview disclosure can state
+    /// the real bound instead of a second hardcoded copy of "800" drifting out of sync.
+    private static let rankedResultsCap = 800
+
     /// os_signpost surface for Instruments. Mirrors FileSystemScanner's subsystem so app-side
     /// and scanner-side spans group together when filtering by subsystem in Instruments.
     private static let log = OSLog(subsystem: "com.rasputinkaiser.StorageScope", category: "scan")
@@ -27,6 +32,7 @@ final class ScanStore: ObservableObject {
     struct ScanOptionsSnapshot: Equatable {
         let includeHiddenFiles: Bool
         let oldFileAgeDays: Int
+        let duplicateCandidateThresholdMB: Int
     }
 
     private struct DerivedCacheKey: Equatable {
@@ -223,6 +229,12 @@ func setSelectedView(_ view: SmartView) {
     }
 
     var oldFileAgeDays: Int { filters.oldFileAgeDays }
+    var duplicateCandidateThresholdMB: Int { filters.duplicateCandidateThresholdMB }
+    var scanRankedResultsCap: Int { Self.rankedResultsCap }
+    /// `maxRetainedItems` isn't overridden when constructing `ScanOptions` in `scan(_:)`,
+    /// so the type's own default is the true bound — read it from a default-initialized
+    /// instance rather than hardcoding a second copy of the number.
+    var scanRetainedItemsCap: Int { ScanOptions().maxRetainedItems }
 
     var activeView: SmartView {
         selectedView ?? .overview
@@ -534,7 +546,25 @@ func setSelectedView(_ view: SmartView) {
         scan(url)
     }
 
+    private var cachedMountedVolumes: [URL]?
+
+    /// Cached so SidebarView's body — which re-evaluates on every store change,
+    /// including per-tick scan progress — doesn't redo `FileManager` volume I/O on
+    /// every render. Refreshed on `SidebarView.onAppear` (app launch) and after every
+    /// successful scan completes, so a volume mounted/unmounted mid-session is picked
+    /// up the next time the user finishes a scan rather than only on relaunch.
     var mountedVolumes: [URL] {
+        if let cachedMountedVolumes { return cachedMountedVolumes }
+        let resolved = resolveMountedVolumes()
+        cachedMountedVolumes = resolved
+        return resolved
+    }
+
+    func refreshMountedVolumes() {
+        cachedMountedVolumes = resolveMountedVolumes()
+    }
+
+    private func resolveMountedVolumes() -> [URL] {
         let keys: [URLResourceKey] = [
             .volumeNameKey,
             .volumeIsBrowsableKey,
@@ -667,8 +697,8 @@ func setSelectedView(_ view: SmartView) {
             includeHidden: filters.includeHiddenFiles,
             oldFileAgeDays: filters.oldFileAgeDays,
             largeFileThreshold: thresholds.largeFileThreshold,
-            duplicateCandidateThreshold: thresholds.duplicateCandidateThreshold,
-            maxRankedResults: 800
+            duplicateCandidateThreshold: Int64(filters.duplicateCandidateThresholdMB) * 1_000_000,
+            maxRankedResults: Self.rankedResultsCap
         )
         let optionsSnapshot = currentScanOptions
         let scanCancellation = ScanCancellation()
@@ -785,6 +815,7 @@ func setSelectedView(_ view: SmartView) {
                     currentPath: "Scan complete"
                 )
                 isScanning = false
+                refreshMountedVolumes()
                 clearActiveScan(scanID, cancellation: scanCancellation)
             } catch FileSystemScannerError.cancelled {
                 guard isCurrentScan(scanID, cancellation: scanCancellation) else {
@@ -1541,7 +1572,8 @@ func setSelectedView(_ view: SmartView) {
     private var currentScanOptions: ScanOptionsSnapshot {
         ScanOptionsSnapshot(
             includeHiddenFiles: filters.includeHiddenFiles,
-            oldFileAgeDays: filters.oldFileAgeDays
+            oldFileAgeDays: filters.oldFileAgeDays,
+            duplicateCandidateThresholdMB: filters.duplicateCandidateThresholdMB
         )
     }
 

Sources/StorageScope/Support/CardBackground.swift

@@ -8,6 +8,11 @@ extension View {
     /// default radius matches the existing 8/8 split that ships today.
     func cardBackground(_ material: Material = .regular, radius: CGFloat = 12) -> some View {
         background(material, in: RoundedRectangle(cornerRadius: radius))
+            // Soft layered elevation instead of a flat fill — adapts to light/dark via
+            // NSColor.shadowColor rather than a fixed black, and stays subtle enough not
+            // to compete with WelcomeCapabilityCard's own stronger hover shadow.
+            .shadow(color: Color(nsColor: .shadowColor).opacity(0.05), radius: 1, y: 1)
+            .shadow(color: Color(nsColor: .shadowColor).opacity(0.05), radius: 4, y: 2)
     }
 
     /// Selection highlight tint. Default opacity (0.18) matches list rows and cards;

Sources/StorageScope/Support/FilterRecoveryView.swift

@@ -62,11 +62,16 @@ struct FilterRecoveryView: View {
                 }
             }
         } actions: {
-            Button(clearTitle) {
-                clearAction()
+            // Only show Clear when there's actually something to clear — with no active
+            // filters this button was previously a visible no-op, which is what made BUG-1's
+            // "no items" empty states read as broken rather than as honest "nothing here".
+            if !filters.isEmpty {
+                Button(clearTitle) {
+                    clearAction()
+                }
+                .buttonStyle(.borderedProminent)
+                .controlSize(.small)
             }
-            .buttonStyle(.borderedProminent)
-            .controlSize(.small)
         }
     }
 

Sources/StorageScope/Support/PressableRowButtonStyle.swift

@@ -0,0 +1,18 @@
+import SwiftUI
+
+/// Tactile press feedback for plain-styled row buttons (StorageItemRow, TreeNodeRow,
+/// StorageMapRow, DuplicateFileRow, CleanupCandidateRow). Visuals (hover tint, selection
+/// background) stay exactly as `.plain` already renders them; this only adds the press
+/// scale. 0.96 per the interface-polish rubric — below 0.95 reads as exaggerated for a
+/// list row.
+struct PressableRowButtonStyle: ButtonStyle {
+    func makeBody(configuration: Configuration) -> some View {
+        configuration.label
+            .scaleEffect(configuration.isPressed ? 0.96 : 1)
+            .animation(.easeOut(duration: 0.12), value: configuration.isPressed)
+    }
+}
+
+extension ButtonStyle where Self == PressableRowButtonStyle {
+    static var pressableRow: PressableRowButtonStyle { PressableRowButtonStyle() }
+}

Sources/StorageScope/Views/CleanupReviewView.swift

@@ -359,7 +359,7 @@ private struct CleanupCandidateRow: View, Equatable {
             .background(isHovered && !isSelected ? Color.primary.opacity(0.04) : Color.clear, in: RoundedRectangle(cornerRadius: 8))
             .contentShape(Rectangle())
         }
-        .buttonStyle(.plain)
+        .buttonStyle(.pressableRow)
         .onHover { isHovered = $0 }
         .accessibilityElement(children: .ignore)
         .accessibilityLabel("\(candidate.item.name), \(candidate.kind.displayName), \(StorageFormat.bytes(candidate.reclaimableBytes))")

Sources/StorageScope/Views/DuplicateCandidatesView.swift

@@ -24,7 +24,9 @@ struct DuplicateCandidatesView: View {
                     FilterRecoveryView(
                         title: "No Duplicate Leads",
                         systemImage: "checkmark.seal",
-                        description: store.hasActiveDisplayFilters ? "No duplicate leads match the active display filters." : "Try scanning a broader folder.",
+                        description: store.hasActiveDisplayFilters
+                            ? "No duplicate leads match the active display filters."
+                            : "No files at or above \(store.duplicateCandidateThresholdMB) MB had matching sizes. Lower the duplicate threshold in Settings to include smaller files.",
                         filters: store.activeDisplayFilterDescriptions,
                         state: store.displayRecoveryState,
                         clearTitle: "Clear Filters"
@@ -278,6 +280,7 @@ private struct DuplicateItemList: View {
                 } onCopyPath: {
                     onCopyPath(item)
                 }
+                .equatable()
 
                 if index < items.index(before: items.endIndex) {
                     Divider()
@@ -287,7 +290,7 @@ private struct DuplicateItemList: View {
     }
 }
 
-private struct DuplicateFileRow: View {
+private struct DuplicateFileRow: View, Equatable {
     let item: StorageItem
     let isKeeper: Bool
     let isSelected: Bool
@@ -298,6 +301,11 @@ private struct DuplicateFileRow: View {
     let onCopyPath: () -> Void
     @State private var isHovered = false
 
+    // Excludes the closures: not Equatable, and freshly allocated per render anyway.
+    static func == (lhs: DuplicateFileRow, rhs: DuplicateFileRow) -> Bool {
+        lhs.item == rhs.item && lhs.isKeeper == rhs.isKeeper && lhs.isSelected == rhs.isSelected
+    }
+
     var body: some View {
         Button(action: onSelect) {
             HStack {
@@ -325,7 +333,7 @@ private struct DuplicateFileRow: View {
             .contentShape(Rectangle())
             .background(isHovered && !isSelected ? Color.primary.opacity(0.04) : Color.clear)
         }
-        .buttonStyle(.plain)
+        .buttonStyle(.pressableRow)
         .onHover { isHovered = $0 }
         .accessibilityElement(children: .ignore)
         .accessibilityLabel("\(item.name), file, \(StorageFormat.bytes(item.displaySize))\(isKeeper ? ", keeper" : "")")

Sources/StorageScope/Views/OverviewView.swift

@@ -8,6 +8,12 @@ struct OverviewView: View {
         ScrollView {
             VStack(alignment: .leading, spacing: 18) {
                 if store.scan != nil {
+                    ScanLimitsDisclosure(
+                        rankedResultsCap: store.scanRankedResultsCap,
+                        duplicateThresholdMB: store.duplicateCandidateThresholdMB,
+                        retainedItemsCap: store.scanRetainedItemsCap
+                    )
+
                     ReclaimPlanView(
                         plan: store.reclaimPlan,
                         activeFilters: store.activeCleanupFilterDescriptions
@@ -17,9 +23,10 @@ struct OverviewView: View {
                         perform(action)
                     }
 
-                    SizeDistributionView(store: store)
-
                     let allOverviewItems = store.items(for: .overview)
+
+                    SizeDistributionView(store: store, overviewItems: allOverviewItems)
+
                     let overviewItems = Array(allOverviewItems.prefix(12))
                     let isFiltered = store.hasActiveDisplayFilters
                     HStack(alignment: .top, spacing: 16) {
@@ -78,6 +85,33 @@ struct OverviewView: View {
     }
 }
 
+/// Collapsed-by-default disclosure stating the active scan bounds. Without this, a ranked
+/// list capped at 800 or a duplicate group missing because a file fell under the configured
+/// threshold reads as "broken" rather than "working as designed" — see 6.1-PLAN.md U-3.
+private struct ScanLimitsDisclosure: View {
+    let rankedResultsCap: Int
+    let duplicateThresholdMB: Int
+    let retainedItemsCap: Int
+
+    var body: some View {
+        DisclosureGroup {
+            VStack(alignment: .leading, spacing: 4) {
+                Text("Largest Files, Largest Folders, and similar ranked lists show the top \(rankedResultsCap.formatted()) matches.")
+                Text("Duplicate detection considers files \(duplicateThresholdMB) MB or larger.")
+                Text("Folder Tree and Storage Map retain up to \(retainedItemsCap.formatted()) of the largest items.")
+            }
+            .font(.caption)
+            .foregroundStyle(.secondary)
+            .padding(.top, 4)
+        } label: {
+            Label("Scan limits", systemImage: "info.circle")
+                .font(.caption.weight(.medium))
+                .foregroundStyle(.secondary)
+        }
+        .accessibilityLabel("Scan limits disclosure")
+    }
+}
+
 private func previewCountLabel(visible: Int, total: Int) -> String {
     guard total > visible else {
         return "\(visible.formatted()) items"
@@ -209,10 +243,10 @@ private struct ReclaimPlanSectionCard: View {
 
 private struct SizeDistributionView: View {
     @ObservedObject var store: ScanStore
+    let overviewItems: [StorageScopeCore.StorageItem]
 
     var body: some View {
         VStack(alignment: .leading, spacing: 12) {
-            let overviewItems = store.items(for: .overview)
             let items = Array(overviewItems.prefix(10))
 
             VStack(alignment: .leading, spacing: 3) {
@@ -249,6 +283,7 @@ private struct SizeDistributionView: View {
                             ) {
                                 store.selectedItemID = item.id
                             }
+                            .equatable()
                             if index < items.count - 1 {
                                 Divider()
                             }
@@ -269,13 +304,19 @@ private struct SizeDistributionView: View {
     }
 }
 
-private struct StorageMapRow: View {
+private struct StorageMapRow: View, Equatable {
     let item: StorageScopeCore.StorageItem
     let maxSize: Int64
     let isSelected: Bool
     let onTap: () -> Void
     @State private var isHovered = false
 
+    // Excludes `onTap`: closures aren't Equatable and every row's closure is
+    // freshly allocated per render anyway, same pattern as StorageItemRow.
+    static func == (lhs: StorageMapRow, rhs: StorageMapRow) -> Bool {
+        lhs.item == rhs.item && lhs.maxSize == rhs.maxSize && lhs.isSelected == rhs.isSelected
+    }
+
     var body: some View {
         Button(action: onTap) {
             HStack(spacing: 12) {
@@ -303,6 +344,7 @@ private struct StorageMapRow: View {
                             }
                     }
                     .frame(height: 8)
+                    .accessibilityHidden(true)
                 }
             }
             .padding(.horizontal, 12)
@@ -311,8 +353,12 @@ private struct StorageMapRow: View {
             .selectionBackground(isSelected: isSelected)
             .background(isHovered && !isSelected ? Color.primary.opacity(0.04) : Color.clear)
         }
-        .buttonStyle(.plain)
+        .buttonStyle(.pressableRow)
         .onHover { isHovered = $0 }
+        .accessibilityElement(children: .ignore)
+        .accessibilityLabel("\(item.name), \(StorageFormat.bytes(item.displaySize))")
+        .accessibilityValue(isSelected ? "Selected" : "Not selected")
+        .accessibilityHint("Selects this storage item")
     }
 }
 

Sources/StorageScope/Views/SettingsView.swift

@@ -11,6 +11,7 @@ struct SettingsView: View {
             SettingsSection(title: "Scan Options") {
                 Toggle("Include hidden files", isOn: store.filterBinding(\.includeHiddenFiles))
                 Stepper("Treat files older than \(store.oldFileAgeDays) days as old", value: store.filterBinding(\.oldFileAgeDays), in: 30...1440, step: 30)
+                Stepper("Detect duplicates \(store.duplicateCandidateThresholdMB) MB or larger", value: store.filterBinding(\.duplicateCandidateThresholdMB), in: 1...500, step: 1)
 
                 if let status = store.scanOptionsStatusText {
                     HStack {
@@ -26,7 +27,7 @@ struct SettingsView: View {
                     }
                 }
 
-                SettingsFootnote("Hidden files and old-file age affect scan results. Existing results keep their previous scan options until you rescan.")
+                SettingsFootnote("Hidden files, old-file age, and the duplicate threshold affect scan results. Existing results keep their previous scan options until you rescan.")
             }
 
             Divider()

Sources/StorageScope/Views/SidebarView.swift

@@ -81,6 +81,9 @@ struct SidebarView: View {
             ScanStatusFooter(store: store)
         }
         .background(.bar)
+        .onAppear {
+            store.refreshMountedVolumes()
+        }
     }
 }
 
@@ -283,6 +286,7 @@ private struct ScanStatusFooter: View {
                     .font(.caption2)
                     .foregroundStyle(.tertiary)
                     .lineLimit(2)
+                    .help(scan.rootURL.path)
             } else {
                 Label("No scan yet", systemImage: "internaldrive")
                     .font(.headline)

Sources/StorageScope/Views/StorageItemTable.swift

@@ -274,6 +274,7 @@ private struct StorageItemRow: View, Equatable {
                             .foregroundStyle(.secondary)
                             .lineLimit(1)
                             .truncationMode(.middle)
+                            .help(item.url.path)
                     }
                 }
                 .frame(minWidth: 220, maxWidth: .infinity, alignment: .leading)
@@ -296,7 +297,7 @@ private struct StorageItemRow: View, Equatable {
             .selectionBackground(isSelected: isSelected)
             .background(isHovered && !isSelected ? Color.primary.opacity(0.04) : Color.clear)
         }
-        .buttonStyle(.plain)
+        .buttonStyle(.pressableRow)
         .onHover { isHovered = $0 }
         .accessibilityElement(children: .ignore)
         .accessibilityLabel("\(item.name), \(StorageFormat.label(for: item.kind)), \(StorageFormat.bytes(item.displaySize))")