fix: align canvas defaults and A2UI auto-nav

apps/macos/Sources/Clawdis/CanvasManager.swift

@@ -11,6 +11,12 @@ final class CanvasManager {
 
     private var panelController: CanvasWindowController?
     private var panelSessionKey: String?
+    private var lastAutoA2UIUrl: String?
+    private var gatewayWatchTask: Task<Void, Never>?
+
+    private init() {
+        self.startGatewayObserver()
+    }
 
     var onPanelVisibilityChanged: ((Bool) -> Void)?
 
@@ -60,6 +66,7 @@ final class CanvasManager {
                     effectiveTarget: normalizedTarget)
             }
 
+            self.maybeAutoNavigateToA2UIAsync(controller: controller)
             return CanvasShowResult(
                 directory: controller.directoryPath,
                 target: target,
@@ -93,6 +100,9 @@ final class CanvasManager {
         Self.logger.debug("showDetailed showCanvas effectiveTarget=\(effectiveTarget, privacy: .public)")
         controller.showCanvas(path: effectiveTarget)
         Self.logger.debug("showDetailed showCanvas done")
+        if normalizedTarget == nil {
+            self.maybeAutoNavigateToA2UIAsync(controller: controller)
+        }
 
         return self.makeShowResult(
             directory: controller.directoryPath,
@@ -124,6 +134,55 @@ final class CanvasManager {
         return try await controller.snapshot(to: outPath)
     }
 
+    // MARK: - Gateway A2UI auto-nav
+
+    private func startGatewayObserver() {
+        self.gatewayWatchTask?.cancel()
+        self.gatewayWatchTask = Task { [weak self] in
+            guard let self else { return }
+            let stream = await GatewayConnection.shared.subscribe(bufferingNewest: 1)
+            for await push in stream {
+                await self.handleGatewayPush(push)
+            }
+        }
+    }
+
+    private func handleGatewayPush(_ push: GatewayPush) {
+        guard case let .snapshot(snapshot) = push else { return }
+        let a2uiUrl = Self.resolveA2UIHostUrl(from: snapshot.canvashosturl)
+        guard let controller = self.panelController else { return }
+        self.maybeAutoNavigateToA2UI(controller: controller, a2uiUrl: a2uiUrl)
+    }
+
+    private func maybeAutoNavigateToA2UIAsync(controller: CanvasWindowController) {
+        Task { [weak self] in
+            guard let self else { return }
+            let a2uiUrl = await self.resolveA2UIHostUrl()
+            await MainActor.run {
+                guard self.panelController === controller else { return }
+                self.maybeAutoNavigateToA2UI(controller: controller, a2uiUrl: a2uiUrl)
+            }
+        }
+    }
+
+    private func maybeAutoNavigateToA2UI(controller: CanvasWindowController, a2uiUrl: String?) {
+        guard let a2uiUrl else { return }
+        guard controller.shouldAutoNavigateToA2UI(lastAutoTarget: self.lastAutoA2UIUrl) else { return }
+        controller.load(target: a2uiUrl)
+        self.lastAutoA2UIUrl = a2uiUrl
+    }
+
+    private func resolveA2UIHostUrl() async -> String? {
+        let raw = await GatewayConnection.shared.canvasHostUrl()
+        return Self.resolveA2UIHostUrl(from: raw)
+    }
+
+    private static func resolveA2UIHostUrl(from raw: String?) -> String? {
+        let trimmed = raw?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
+        guard !trimmed.isEmpty, let base = URL(string: trimmed) else { return nil }
+        return base.appendingPathComponent("__clawdis__/a2ui/").absoluteString
+    }
+
     // MARK: - Anchoring
 
     private static func mouseAnchorProvider() -> NSRect? {

apps/macos/Sources/Clawdis/CanvasWindow.swift

@@ -43,6 +43,7 @@ final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NS
     private let container: HoverChromeContainerView
     let presentation: CanvasPresentation
     private var preferredPlacement: CanvasPlacement?
+    private(set) var currentTarget: String?
 
     var onVisibilityChanged: ((Bool) -> Void)?
 
@@ -237,6 +238,7 @@ final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NS
 
     func load(target: String) {
         let trimmed = target.trimmingCharacters(in: .whitespacesAndNewlines)
+        self.currentTarget = trimmed
 
         if let url = URL(string: trimmed), let scheme = url.scheme?.lowercased() {
             if scheme == "https" || scheme == "http" {
@@ -340,6 +342,18 @@ final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NS
         self.sessionDir.path
     }
 
+    func shouldAutoNavigateToA2UI(lastAutoTarget: String?) -> Bool {
+        let trimmed = (self.currentTarget ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
+        if trimmed.isEmpty || trimmed == "/" { return true }
+        if let lastAuto = lastAutoTarget?.trimmingCharacters(in: .whitespacesAndNewlines),
+           !lastAuto.isEmpty,
+           trimmed == lastAuto
+        {
+            return true
+        }
+        return false
+    }
+
     // MARK: - Window
 
     private static func makeWindow(for presentation: CanvasPresentation, contentView: NSView) -> NSWindow {