fix: VaultViewModel forwards session objectWillChange explicitly

Prevents EntryListView refresh from relying on an implicit SwiftUI
re-render cascade through ContentView; now vaultVM itself publishes
when session.database changes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WYqycDFsynHH9VnnK7LNSf

MyPass/ViewModels/VaultViewModel.swift

@@ -10,9 +10,13 @@ final class VaultViewModel: ObservableObject {
     @Published var errorMessage: String?
 
     let session: VaultSession
+    private var sessionCancellable: AnyCancellable?
 
     init(session: VaultSession) {
         self.session = session
+        sessionCancellable = session.objectWillChange.sink { [weak self] in
+            self?.objectWillChange.send()
+        }
     }
 
     /// All entries in the vault, flattened with their group breadcrumb, before any filtering.