UI redesign Phase 1: NavigationSplitView with collapsible sidebar

- Replace root VStack with NavigationSplitView (2-column, collapsible sidebar)
- Add SidebarView: new chat button, conversation search, list with swipe actions
- Slim HeaderView to text-only (provider + model + star); remove all icon rows
- Move status pills (Online, MCP, Synced) to footer right side
- Remove version number and shortcut hints from footer
- Add resizable InputBar with drag handle (persisted height) and globe/network.slash online toggle
- Fix Norwegian menu appearing on English systems (CFBundleLocalizations in Info.plist)
- Add View menu (Model Info, History, Stats, Credits, Online Mode toggle ⌘⇧O)
- Add ⌘L as alias for Search Conversations (muscle memory for /load users)
- Add Check for Updates to Help menu with download URL from Gitea API
- Add one-time Intel/Rosetta deprecation warning on first launch
- Swift 6: fix self.Self.isoString() call sites in DatabaseService

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

oAI/Views/Main/HeaderView.swift

@@ -2,7 +2,8 @@
 //  HeaderView.swift
 //  oAI
 //
-//  Header bar with provider, model, and stats
+//  Slim header — provider, model name, star only.
+//  Status pills and stats live in SidebarView and FooterView respectively.
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 // Copyright (C) 2026 Rune Olsen
@@ -28,18 +29,13 @@ import SwiftUI
 struct HeaderView: View {
     let provider: Settings.Provider
     let model: ModelInfo?
-    let stats: SessionStats
-    let onlineMode: Bool
-    let mcpEnabled: Bool
-    let mcpStatus: String?
     let onModelSelect: () -> Void
     let onProviderChange: (Settings.Provider) -> Void
     private let settings = SettingsService.shared
     private let registry = ProviderRegistry.shared
-    private let gitSync = GitSyncService.shared
 
     var body: some View {
-        HStack(spacing: 20) {
+        HStack(spacing: 12) {
             // Provider picker dropdown — only shows configured providers
             Menu {
                 ForEach(registry.configuredProviders, id: \.self) { p in
@@ -75,7 +71,7 @@ struct HeaderView: View {
             .fixedSize()
             .help("Switch provider")
 
-            // Model info (clickable → model selector)
+            // Model name (clickable → model selector)
             Button(action: onModelSelect) {
                 if let model = model {
                     HStack(spacing: 6) {
@@ -116,7 +112,6 @@ struct HeaderView: View {
                         Text("No model selected")
                             .font(.system(size: settings.guiTextSize))
                             .foregroundColor(.oaiSecondary)
-
                         Image(systemName: "chevron.down")
                             .font(.caption2)
                             .foregroundColor(.oaiSecondary)
@@ -126,6 +121,7 @@ struct HeaderView: View {
             .buttonStyle(.plain)
             .help("Select model")
 
+            // Favourite star
             if let model = model {
                 let isFav = settings.favoriteModelIds.contains(model.id)
                 Button(action: { settings.toggleFavoriteModel(model.id) }) {
@@ -138,40 +134,9 @@ struct HeaderView: View {
             }
 
             Spacer()
-
-            // Status indicators
-            HStack(spacing: 8) {
-                if model?.capabilities.imageGeneration == true {
-                    StatusPill(icon: "paintbrush", label: "Image", color: .purple)
-                }
-                if onlineMode {
-                    StatusPill(icon: "globe", label: "Online", color: .green)
-                }
-                if mcpEnabled {
-                    StatusPill(icon: "folder", label: "MCP", color: .blue)
-                }
-                if settings.syncEnabled && settings.syncAutoSave {
-                    SyncStatusPill()
-                }
-            }
-
-            // Divider between status and stats
-            if onlineMode || mcpEnabled || model?.capabilities.imageGeneration == true || (settings.syncEnabled && settings.syncAutoSave) {
-                Divider()
-                    .frame(height: 16)
-                    .opacity(0.5)
-            }
-
-            // Quick stats
-            HStack(spacing: 16) {
-                StatItem(icon: "message", value: "\(stats.messageCount)")
-                StatItem(icon: "arrow.up.arrow.down", value: stats.totalTokensDisplay)
-                StatItem(icon: "dollarsign", value: stats.totalCostDisplay)
-            }
-            .font(.caption)
         }
         .padding(.horizontal, 16)
-        .padding(.vertical, 10)
+        .padding(.vertical, 8)
         .background(.ultraThinMaterial)
         .overlay(
             Rectangle()
@@ -182,22 +147,7 @@ struct HeaderView: View {
     }
 }
 
-struct StatItem: View {
-    let icon: String
-    let value: String
-    private let settings = SettingsService.shared
-
-    var body: some View {
-        HStack(spacing: 4) {
-            Image(systemName: icon)
-                .font(.system(size: settings.guiTextSize - 3))
-                .foregroundColor(.oaiSecondary)
-            Text(value)
-                .font(.system(size: settings.guiTextSize - 1, weight: .medium))
-                .foregroundColor(.oaiPrimary)
-        }
-    }
-}
+// MARK: - Status Pills (used by SidebarView)
 
 struct StatusPill: View {
     let icon: String
@@ -284,15 +234,6 @@ struct SyncStatusPill: View {
         HeaderView(
             provider: .openrouter,
             model: ModelInfo.mockModels.first,
-            stats: SessionStats(
-                totalInputTokens: 125,
-                totalOutputTokens: 434,
-                totalCost: 0.00111,
-                messageCount: 4
-            ),
-            onlineMode: true,
-            mcpEnabled: true,
-            mcpStatus: "MCP",
             onModelSelect: {},
             onProviderChange: { _ in }
         )