feat: add group + search filtering to VaultViewModel

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WYqycDFsynHH9VnnK7LNSf

MyPass/ViewModels/VaultViewModel.swift

@@ -1,8 +1,4 @@
-//
-//  VaultViewModel.swift
-//  MyPass
-//
-
+// MyPass/ViewModels/VaultViewModel.swift
 import Foundation
 import Combine
 import MyPassCore
@@ -10,6 +6,7 @@ import MyPassCore
 @MainActor
 final class VaultViewModel: ObservableObject {
     @Published var searchQuery: String = ""
+    @Published var selectedGroupIds: Set<UUID> = []
     @Published var errorMessage: String?
 
     let session: VaultSession
@@ -18,21 +15,32 @@ final class VaultViewModel: ObservableObject {
         self.session = session
     }
 
-    var filteredEntries: [Entry] {
-        guard !searchQuery.isEmpty else { return [] }
-        let q = searchQuery.lowercased()
-        return session.allEntries().filter {
-            $0.title.lowercased().contains(q)
-            || $0.username.lowercased().contains(q)
-            || $0.url.lowercased().contains(q)
-        }
+    /// All entries in the vault, flattened with their group breadcrumb, before any filtering.
+    private var allFlatEntries: [FlatEntry] {
+        guard let root = session.database?.root else { return [] }
+        return flattenEntries(in: root)
     }
 
-    var isSearching: Bool { !searchQuery.isEmpty }
+    /// Entries after applying the group filter, then the search filter (AND semantics).
+    var displayedEntries: [FlatEntry] {
+        var entries = allFlatEntries
+        if !selectedGroupIds.isEmpty {
+            entries = entries.filter { selectedGroupIds.contains($0.parentGroupId) }
+        }
+        if !searchQuery.isEmpty {
+            let q = searchQuery.lowercased()
+            entries = entries.filter {
+                $0.entry.title.lowercased().contains(q)
+                || $0.entry.username.lowercased().contains(q)
+                || $0.entry.url.lowercased().contains(q)
+            }
+        }
+        return entries
+    }
 
-    func deleteEntry(_ entry: Entry, fromGroup group: Group) {
+    func deleteEntry(_ flatEntry: FlatEntry) {
         Task {
-            do { try session.deleteEntry(id: entry.id, fromGroupId: group.id) }
+            do { try session.deleteEntry(id: flatEntry.entry.id, fromGroupId: flatEntry.parentGroupId) }
             catch { errorMessage = error.localizedDescription }
         }
     }