fix(macos): open NSOpenPanel for embedded Control UI file inputs (#94468) (#94612)

Summary:
- The PR wires the macOS Dashboard and Canvas WKWebViews to WKUIDelegate and presents NSOpenPanel for HTML file inputs.
- PR surface: Other +61. Total +61 across 3 files.
- Reproducibility: yes. at source level: current main renders the affected file inputs while the macOS Dashboa ... fore-fix packaged macOS app in this read-only review, but the after-fix screenshots show the real app path.

Automerge notes:
- No ClawSweeper repair was needed after automerge opt-in.

Validation:
- ClawSweeper review passed for head 4f477c4ed0.
- Required merge gates passed before the squash merge.

Prepared head SHA: 4f477c4ed0
Review: https://github.com/openclaw/openclaw/pull/94612#issuecomment-4743165861

Co-authored-by: bbblending <li.mingkang@xydigit.com>

apps/macos/Sources/OpenClaw/CanvasWindowController+UIDelegate.swift

@@ -0,0 +1,32 @@
+import AppKit
+import WebKit
+
+extension CanvasWindowController {
+    // MARK: - WKUIDelegate
+
+    /// Bridges `<input type="file">` clicks in canvas HTML to a native `NSOpenPanel`.
+    /// Without a `WKUIDelegate`, WebKit silently drops the request and file-picker
+    /// buttons in canvas pages do nothing.
+    @MainActor
+    func webView(
+        _ webView: WKWebView,
+        runOpenPanelWith parameters: WKOpenPanelParameters,
+        initiatedByFrame frame: WKFrameInfo,
+        completionHandler: @escaping @MainActor @Sendable ([URL]?) -> Void)
+    {
+        let panel = NSOpenPanel()
+        panel.canChooseFiles = true
+        panel.canChooseDirectories = parameters.allowsDirectories
+        panel.allowsMultipleSelection = parameters.allowsMultipleSelection
+        panel.resolvesAliases = true
+        if let window = self.window {
+            panel.beginSheetModal(for: window) { response in
+                completionHandler(response == .OK ? panel.urls : nil)
+            }
+            return
+        }
+        panel.begin { response in
+            completionHandler(response == .OK ? panel.urls : nil)
+        }
+    }
+}

apps/macos/Sources/OpenClaw/CanvasWindowController.swift

@@ -5,7 +5,7 @@ import OpenClawKit
 import WebKit
 
 @MainActor
-final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NSWindowDelegate {
+final class CanvasWindowController: NSWindowController, WKNavigationDelegate, WKUIDelegate, NSWindowDelegate {
     let sessionKey: String
     private let root: URL
     private let sessionDir: URL
@@ -159,6 +159,7 @@ final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NS
         }
 
         self.webView.navigationDelegate = self
+        self.webView.uiDelegate = self
         self.window?.delegate = self
         self.container.onClose = { [weak self] in
             self?.hideCanvas()

apps/macos/Sources/OpenClaw/DashboardWindowController.swift

@@ -19,7 +19,7 @@ private final class DashboardWindowDragRegionView: NSView {
 }
 
 @MainActor
-final class DashboardWindowController: NSWindowController, WKNavigationDelegate, NSWindowDelegate {
+final class DashboardWindowController: NSWindowController, WKNavigationDelegate, WKUIDelegate, NSWindowDelegate {
     private let webView: WKWebView
     private var currentURL: URL
     private var auth: DashboardWindowAuth
@@ -44,9 +44,37 @@ final class DashboardWindowController: NSWindowController, WKNavigationDelegate,
         super.init(window: window)
 
         self.webView.navigationDelegate = self
+        self.webView.uiDelegate = self
         self.window?.delegate = self
     }
 
+    // MARK: - WKUIDelegate
+
+    /// Bridges `<input type="file">` clicks in the embedded Control UI to a native
+    /// `NSOpenPanel`; without a `WKUIDelegate`, WebKit silently drops the request
+    /// and "Choose image" / file-picker buttons do nothing.
+    func webView(
+        _ webView: WKWebView,
+        runOpenPanelWith parameters: WKOpenPanelParameters,
+        initiatedByFrame frame: WKFrameInfo,
+        completionHandler: @escaping @MainActor @Sendable ([URL]?) -> Void)
+    {
+        let panel = NSOpenPanel()
+        panel.canChooseFiles = true
+        panel.canChooseDirectories = parameters.allowsDirectories
+        panel.allowsMultipleSelection = parameters.allowsMultipleSelection
+        panel.resolvesAliases = true
+        if let window = self.window {
+            panel.beginSheetModal(for: window) { response in
+                completionHandler(response == .OK ? panel.urls : nil)
+            }
+            return
+        }
+        panel.begin { response in
+            completionHandler(response == .OK ? panel.urls : nil)
+        }
+    }
+
     @available(*, unavailable)
     required init?(coder: NSCoder) {
         fatalError("init(coder:) is not supported")