feat: add Linux and Windows named-window routing

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docs/architecture/multi-window-ownership.mdmodified+2-1

Changes to docs/architecture/multi-window-ownership.md

		⋯23 linesShow the 23 lines above this hunk@@ -24,7 +24,8 @@ app-local WebView2 loader; users still need the Microsoft WebView2 Runtime.
24	24
25	25	Linux and Windows keep their live native window/webview pairs in
26	26	`desktop_window_registry.zig`. Page messages are authenticated by the sending
27		-WebKitGTK/WebView2 view; names select a target only after that sender is known.
	27	+WebKitGTK view or the per-WebView2 event subscription; names select a target
	28	+only after that native source is known.
28	29	Replies go back to the requesting view, and lifecycle events go to the changed
29	30	window plus its named handle's creator. Linux must register its `GtkApplication`
30	31	before constructing the first `GtkApplicationWindow`, because the CLI creates

packages/zig/src/desktop_window_registry.zigmodified+10-0

Changes to packages/zig/src/desktop_window_registry.zig

		⋯281 linesShow the 281 lines above this hunk@@ -282,3 +282,13 @@ test "a window keeps its own platform control object" {
282	282	_ = registry.forgetWindow(0x1000);
283	283	try std.testing.expectEqual(@as(usize, 0x2002), registry.byWindow(0x2000).?.context);
284	284	}
	285	+
	286	+test "a stale event subscription id cannot select a reopened window" {
	287	+ var registry: Registry = .{};
	288	+ const old_id = registry.remember(0x1000, 0x1001).?;
	289	+ _ = registry.forgetWindow(0x1000);
	290	+ const reopened_id = registry.remember(0x1000, 0x2001).?;
	291	+ try std.testing.expect(old_id != reopened_id);
	292	+ try std.testing.expect(registry.byId(old_id) == null);
	293	+ try std.testing.expectEqual(@as(usize, 0x2001), registry.byId(reopened_id).?.webview);
	294	+}

packages/zig/src/windows.zigmodified+8-4

Changes to packages/zig/src/windows.zig

		⋯640 linesShow the 640 lines above this hunk@@ -641,6 +641,7 @@ pub const ICoreWebView2PermissionRequestedEventHandler = PermissionRequestedHand
641	641	const WebMessageReceivedHandler = extern struct {
642	642	lpVtbl: *const WebMessageReceivedHandlerVtbl,
643	643	ref_count: c_ulong,
	644	+ window_id: u32,
644	645
645	646	const WebMessageReceivedHandlerVtbl = extern struct {
646	647	QueryInterface: *const fn (*WebMessageReceivedHandler, *const GUID, *?*anyopaque) callconv(.c) HRESULT,
		⋯27 linesShow the 27 lines above this hunk@@ -674,9 +675,12 @@ const WebMessageReceivedHandler = extern struct {
674	675	return remaining;
675	676	}
676	677
677		- fn invoke(_: *WebMessageReceivedHandler, sender: *ICoreWebView2, args: *ICoreWebView2WebMessageReceivedEventArgs) callconv(.c) HRESULT {
678		- // Authenticate with the COM sender, never an id supplied by the page.
679		- const entry = desktop_windows.byWebview(@intFromPtr(sender)) orelse return S_OK;
	678	+ fn invoke(self: *WebMessageReceivedHandler, _: *ICoreWebView2, args: *ICoreWebView2WebMessageReceivedEventArgs) callconv(.c) HRESULT {
	679	+ // The handler is registered on exactly one native WebView2 instance.
	680	+ // Bind its live registry id rather than comparing raw COM interface
	681	+ // pointers, which need not have the same address for one object.
	682	+ const entry = desktop_windows.byId(self.window_id) orelse return S_OK;
	683	+ std.debug.print("[WebView2] Page message received for window {d}\n", .{self.window_id});
680	684	var message_wide: ?LPWSTR = null;
681	685	if (!succeeded(args.lpVtbl.get_WebMessageAsJson(args, &message_wide))) return S_OK;
682	686	const wide = message_wide orelse return S_OK;
		⋯559 linesShow the 559 lines above this hunk@@ -1242,7 +1246,7 @@ pub const Window = struct {
1242	1246	std.debug.print("[WebView2] Native window registered\n", .{});
1243	1247
1244	1248	const message_handler = try std.heap.c_allocator.create(WebMessageReceivedHandler);
1245		- message_handler.* = .{ .lpVtbl = &WebMessageReceivedHandler.vtbl_instance, .ref_count = 1 };
	1249	+ message_handler.* = .{ .lpVtbl = &WebMessageReceivedHandler.vtbl_instance, .ref_count = 1, .window_id = window_id };
1246	1250	var message_token: EventRegistrationToken = .{ .value = 0 };
1247	1251	std.debug.print("[WebView2] Registering page message handler\n", .{});
1248	1252	const message_hr = webview.lpVtbl.add_WebMessageReceived(webview, @ptrCast(message_handler), &message_token);