fix: SMB share enumeration, BrowseView polish, sign out, Login branding

- Fix "Bad Network Name": BrowseView at root "/" for SMB now calls
  listShares() instead of listDirectory with empty share name.
  SMBClient.listShares() filters IPC/admin/hidden ($) shares.
- Add listShares() to NASTransferProtocol; implement in SMB (filters
  ipc/special/$-suffix) and SFTP (returns []).
- BrowseView: premium error state (wifi.exclamationmark icon + Retry
  button with ScaleButtonStyle), empty state, safeAreaInset bottom bar
  replacing toolbar bottomBar (shows current path chip + compact Select
  button), proper disabled state for root selection on SMB.
- FolderRow: replace hardcoded .white with AppTheme.inkInverse for dark
  mode correctness; use folder.fill icon; ScaleButtonStyle for tap feedback.
- LoginView: larger logo (80pt), bolder "Kisani" wordmark (32pt bold),
  tagline, staggered spring entrance animations (0.08-0.36s delay).
- SettingsView: Sign Out button in ACCOUNT section with
  confirmationDialog (destructive, clears connection + resets session).
- ConnectionStore: signOut() resets isSessionActive, onboardingPhotoShown,
  and clears savedConnection (triggers Keychain delete).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Features/Settings/SettingsView.swift

@@ -3,6 +3,7 @@ import SwiftUI
 struct SettingsView: View {
     @EnvironmentObject var store: ConnectionStore
     @EnvironmentObject var lanMonitor: LANMonitor
+    @State private var showSignOutConfirm = false
 
     var body: some View {
         ZStack {
@@ -17,6 +18,7 @@ struct SettingsView: View {
                     connectivitySection
                     remoteAccessSection
                     notificationSection
+                    signOutSection
                 }
                 .padding(.horizontal, AppTheme.hPad)
                 .padding(.top, 20)
@@ -25,6 +27,16 @@ struct SettingsView: View {
         }
         .navigationTitle("Settings")
         .navigationBarTitleDisplayMode(.inline)
+        .confirmationDialog(
+            "Sign out of Kisani?",
+            isPresented: $showSignOutConfirm,
+            titleVisibility: .visible
+        ) {
+            Button("Sign Out & Forget NAS", role: .destructive) { store.signOut() }
+            Button("Cancel", role: .cancel) {}
+        } message: {
+            Text("Your NAS connection and backup settings will be removed from this device.")
+        }
     }
 
     // MARK: — Appearance
@@ -305,4 +317,38 @@ struct SettingsView: View {
             .frame(height: 0.5)
             .padding(.leading, AppTheme.cardPad)
     }
+
+    // MARK: — Sign Out
+
+    private var signOutSection: some View {
+        VStack(alignment: .leading, spacing: 8) {
+            sectionLabel("ACCOUNT")
+
+            Button(action: { showSignOutConfirm = true }) {
+                HStack(spacing: 12) {
+                    Image(systemName: "rectangle.portrait.and.arrow.right")
+                        .font(.system(size: 14, weight: .regular))
+                        .foregroundStyle(AppTheme.destructive)
+                        .frame(width: 20)
+                    Text("Sign Out")
+                        .font(AppTheme.body())
+                        .foregroundStyle(AppTheme.destructive)
+                    Spacer()
+                }
+                .padding(.horizontal, AppTheme.cardPad)
+                .padding(.vertical, 14)
+                .background(AppTheme.surfaceRaised)
+                .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
+                .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
+            }
+            .buttonStyle(ScaleButtonStyle())
+        }
+    }
+
+    private func sectionLabel(_ text: String) -> some View {
+        Text(text)
+            .font(AppTheme.micro())
+            .foregroundStyle(AppTheme.inkTertiary)
+            .padding(.leading, 4)
+    }
 }