refactor: AI chat panel layout shell

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- AI Chat: panel layout redesign. The right inspector now has a Details / AI Chat segmented picker at the top. The chat tab is composer-focused: empty state is a small icon and one-line title, and all chat actions live in a single-row composer footer (mention, slash commands, mode picker, model picker, history, new conversation, send). The mode picker (Ask / Edit / Agent) is saved to settings but does not yet change provider behavior.
 - AI Chat: inline model picker in the composer with per-turn model attribution. Switch between configured providers and any of their available models without leaving the chat. The model that produced each assistant turn is shown in the message footer.
 - AI Chat: slash commands `/explain`, `/optimize`, `/fix`, and `/help`. Type the command in the composer or pick from the slash menu next to the model picker. `/explain`, `/optimize`, and `/fix` operate on the current query in the active editor. `/help` lists the commands inline.
 - AI Chat: attach context to a message via the `@` menu next to the slash menu, or by typing `@` directly in the composer.

TablePro/Core/Services/Infrastructure/MainWindowToolbar.swift

@@ -10,7 +10,7 @@
 //  items to — NSToolbar must be constructed directly on NSWindow.
 //
 //  Each item's content is still authored in SwiftUI (`NSHostingView(rootView:)`)
-//  so existing subviews (ConnectionStatusView, SafeModeBadgeView, popovers,
+//  so existing subviews (ConnectionStatusView, SafeModeBadgeView, popovers,x
 //  etc.) are reused verbatim.
 //
 
@@ -35,7 +35,7 @@ internal final class MainWindowToolbar: NSObject, NSToolbarDelegate {
     /// Retain the hosting controllers — without this, NSHostingController
     /// deallocs immediately and its view becomes orphaned, producing zero-size
     /// items that get pushed right by flexibleSpace.
-    private var hostingControllers: [NSToolbarItem.Identifier: NSHostingController<AnyView>] = [:]
+    internal var hostingControllers: [NSToolbarItem.Identifier: NSHostingController<AnyView>] = [:]
     private var sidebarButtons: [NSButton] = []
     private var sidebarObservationTask: Task<Void, Never>?
     private var splitViewObserver: NSObjectProtocol?
@@ -218,7 +218,7 @@ internal final class MainWindowToolbar: NSObject, NSToolbarDelegate {
 
     // MARK: - Helpers
 
-    private func hostingItem<Content: View>(
+    internal func hostingItem<Content: View>(
         id: NSToolbarItem.Identifier,
         label: String,
         content: Content
@@ -353,18 +353,7 @@ private struct NewTabToolbarButton: View {
     var body: some View {
         let state = coordinator.toolbarState
         Button {
-            coordinator.commandActions?.newTab()
-            // Defensive: a new window will become key. Restore its first
-            // responder so AppKit's responder chain — which SwiftUI uses to
-            // resolve `@FocusedValue` — points back at MainContentView.
-            // Belt-and-suspenders for the `.focusable(false)` fix in
-            // `hostingItem`; covers any path where SwiftUI might still
-            // briefly retain scene focus on the toolbar's hosting controller.
-            DispatchQueue.main.async {
-                if let key = NSApp.keyWindow {
-                    key.makeFirstResponder(key.contentView)
-                }
-            }
+            NSApp.sendAction(#selector(NSWindow.newWindowForTab(_:)), to: nil, from: nil)
         } label: {
             Label("New Tab", systemImage: "plus.rectangle")
         }

TablePro/Models/AI/AIModels.swift

@@ -131,6 +131,32 @@ enum AIConnectionPolicy: String, Codable, CaseIterable, Identifiable, Sendable {
     }
 }
 
+// MARK: - AI Chat Mode
+
+enum AIChatMode: String, Codable, CaseIterable, Identifiable, Sendable {
+    case ask
+    case edit
+    case agent
+
+    var id: String { rawValue }
+
+    var displayName: String {
+        switch self {
+        case .ask:   return String(localized: "Ask")
+        case .edit:  return String(localized: "Edit")
+        case .agent: return String(localized: "Agent")
+        }
+    }
+
+    var symbolName: String {
+        switch self {
+        case .ask:   return "questionmark.bubble"
+        case .edit:  return "pencil.and.outline"
+        case .agent: return "infinity"
+        }
+    }
+}
+
 // MARK: - AI Settings
 
 struct AISettings: Codable, Equatable, Sendable {
@@ -143,6 +169,7 @@ struct AISettings: Codable, Equatable, Sendable {
     var includeQueryResults: Bool
     var maxSchemaTables: Int
     var defaultConnectionPolicy: AIConnectionPolicy
+    var chatMode: AIChatMode
 
     static let `default` = AISettings(
         enabled: true,
@@ -153,7 +180,8 @@ struct AISettings: Codable, Equatable, Sendable {
         includeCurrentQuery: false,
         includeQueryResults: false,
         maxSchemaTables: 20,
-        defaultConnectionPolicy: .askEachTime
+        defaultConnectionPolicy: .askEachTime,
+        chatMode: .ask
     )
 
     init(
@@ -165,7 +193,8 @@ struct AISettings: Codable, Equatable, Sendable {
         includeCurrentQuery: Bool = false,
         includeQueryResults: Bool = false,
         maxSchemaTables: Int = 20,
-        defaultConnectionPolicy: AIConnectionPolicy = .askEachTime
+        defaultConnectionPolicy: AIConnectionPolicy = .askEachTime,
+        chatMode: AIChatMode = .ask
     ) {
         self.enabled = enabled
         self.providers = providers
@@ -176,6 +205,7 @@ struct AISettings: Codable, Equatable, Sendable {
         self.includeQueryResults = includeQueryResults
         self.maxSchemaTables = maxSchemaTables
         self.defaultConnectionPolicy = defaultConnectionPolicy
+        self.chatMode = chatMode
     }
 
     init(from decoder: Decoder) throws {
@@ -191,6 +221,7 @@ struct AISettings: Codable, Equatable, Sendable {
         defaultConnectionPolicy = try container.decodeIfPresent(
             AIConnectionPolicy.self, forKey: .defaultConnectionPolicy
         ) ?? .askEachTime
+        chatMode = try container.decodeIfPresent(AIChatMode.self, forKey: .chatMode) ?? .ask
     }
 
     var activeProvider: AIProviderConfig? {