fix(windows): use webview2_com built-in handler instead of #[implement]

The previous approach used windows::core::implement to manually implement
ICoreWebView2PermissionRequestedEventHandler_Impl, but the sealed
IUnknownImpl constraint in webview2-com prevents external #[implement]
usage — you must use the crate's own pre-built handler types.

Replace with PermissionRequestedEventHandler::create() which wraps the
closure and handles COM ref-counting internally. Also removes the now-
unused windows = "0.61" direct dependency.

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

src-tauri/Cargo.toml

@@ -44,7 +44,6 @@ tauri-plugin-updater = "2"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 webview2-com = "0.38"
-windows = { version = "0.61", features = [] }
 
 [lib]
 name = "app_lib"

src-tauri/src/lib.rs

@@ -3,46 +3,9 @@
     windows_subsystem = "windows"
 )]
 
-// mod menu;
-
 use tauri::{webview::{NewWindowResponse, WebviewWindowBuilder}, WebviewUrl};
 use tauri_plugin_opener::OpenerExt;
 
-// Automatically grant camera and microphone permissions in WebView2 (Windows).
-// macOS handles this via Info.plist; Windows requires an explicit PermissionRequested handler.
-#[cfg(target_os = "windows")]
-mod win_permissions {
-    use webview2_com::Microsoft::Web::WebView2::Win32::{
-        ICoreWebView2, ICoreWebView2PermissionRequestedEventArgs,
-        ICoreWebView2PermissionRequestedEventHandler,
-        ICoreWebView2PermissionRequestedEventHandler_Impl,
-        COREWEBVIEW2_PERMISSION_KIND_CAMERA, COREWEBVIEW2_PERMISSION_KIND_MICROPHONE,
-        COREWEBVIEW2_PERMISSION_STATE_ALLOW,
-    };
-    use windows::core::implement;
-
-    #[implement(ICoreWebView2PermissionRequestedEventHandler)]
-    pub struct PermissionHandler;
-
-    impl ICoreWebView2PermissionRequestedEventHandler_Impl for PermissionHandler {
-        fn Invoke(
-            &self,
-            _sender: Option<&ICoreWebView2>,
-            args: Option<&ICoreWebView2PermissionRequestedEventArgs>,
-        ) -> windows::core::Result<()> {
-            if let Some(args) = args {
-                let kind = unsafe { args.PermissionKind() }?;
-                if kind == COREWEBVIEW2_PERMISSION_KIND_MICROPHONE
-                    || kind == COREWEBVIEW2_PERMISSION_KIND_CAMERA
-                {
-                    unsafe { args.SetState(COREWEBVIEW2_PERMISSION_STATE_ALLOW) }?;
-                }
-            }
-            Ok(())
-        }
-    }
-}
-
 pub fn run() {
     let port: u16 = 44548;
     let context = tauri::generate_context!();
@@ -71,19 +34,39 @@ pub fn run() {
                     NewWindowResponse::Deny
                 });
 
+            // Grant camera and microphone to WebView2 automatically.
+            // Windows requires an explicit PermissionRequested COM event handler;
+            // macOS uses Info.plist.
             #[cfg(target_os = "windows")]
             let builder = builder.with_webview(|webview| {
-                use webview2_com::Microsoft::Web::WebView2::Win32::ICoreWebView2PermissionRequestedEventHandler;
-                use windows::core::EventRegistrationToken;
-                use win_permissions::PermissionHandler;
+                use webview2_com::{
+                    Microsoft::Web::WebView2::Win32::{
+                        COREWEBVIEW2_PERMISSION_KIND_CAMERA,
+                        COREWEBVIEW2_PERMISSION_KIND_MICROPHONE,
+                        COREWEBVIEW2_PERMISSION_STATE_ALLOW,
+                    },
+                    PermissionRequestedEventHandler,
+                };
 
                 let controller = webview.controller();
                 if let Ok(core) = unsafe { controller.CoreWebView2() } {
-                    let handler: ICoreWebView2PermissionRequestedEventHandler =
-                        PermissionHandler.into();
-                    let mut token = EventRegistrationToken(0);
+                    let handler = PermissionRequestedEventHandler::create(Box::new(
+                        |_sender, args| {
+                            if let Some(args) = args {
+                                let kind = unsafe { args.PermissionKind() }?;
+                                if kind == COREWEBVIEW2_PERMISSION_KIND_MICROPHONE
+                                    || kind == COREWEBVIEW2_PERMISSION_KIND_CAMERA
+                                {
+                                    unsafe {
+                                        args.SetState(COREWEBVIEW2_PERMISSION_STATE_ALLOW)
+                                    }?;
+                                }
+                            }
+                            Ok(())
+                        },
+                    ));
+                    let mut token = Default::default();
                     let _ = unsafe { core.add_PermissionRequested(&handler, &mut token) };
-                    std::mem::forget(handler);
                 }
             });