feat: add Linux and Windows named-window routing

Review threads live on the whole diff, not on one commit, so none are shown here - a thread's line means something in the branch's final form, and painting it into an intermediate step would put it on code it is not about.

docs/architecture/multi-window-ownership.mdmodified+24-17

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

		@@ -1,7 +1,7 @@
1	1	# Multi-window ownership
2	2
3	3	This document records Craft's current multi-window ownership contract. It is
4		-both a map of the implemented macOS behavior and a boundary around the choices
	4	+both a map of the implemented desktop behavior and a boundary around the choices
5	5	that are still open. A process-global Zig object is not automatically a
6	6	single-window bug: the important question is whether it is a shared service or
7	7	whether it stores a window-specific target.
		⋯2 linesShow the 2 lines above this hunk@@ -10,17 +10,25 @@ whether it stores a window-specific target.
10	10
11	11	| Area | macOS | Linux | Windows |
12	12	| --- | --- | --- | --- |
13		-| Runtime creation from `createWindow()` | Implemented | Not wired to the SDK handle contract | Not wired to the SDK handle contract |
14		-| Stable named handles | Implemented | Not implemented | Not implemented |
15		-| Sender-authenticated local actions | Implemented | Not implemented | Not implemented |
16		-| Named cross-window actions | Implemented | Not implemented | Not implemented |
17		-| Per-window lifecycle events | Implemented | Not implemented | Not implemented |
18		-| Permanent destroy and cleanup | Implemented for named windows | Not implemented | Not implemented |
	13	+| Runtime creation from `createWindow()` | Implemented | Implemented; GUI smoke in CI | Implemented; cross-build in CI |
	14	+| Stable named handles | Implemented | Implemented | Implemented |
	15	+| Sender-authenticated local actions | Implemented | Implemented through WebKitGTK | Implemented through WebView2 |
	16	+| Named cross-window actions | Implemented | Implemented for core controls | Implemented for core controls |
	17	+| Per-window lifecycle events | Implemented | Implemented | Implemented |
	18	+| Permanent destroy and cleanup | Implemented for named windows | Implemented on close/destroy | Implemented on close/destroy |
19	19	| Modal and parent relationships | Unspecified | Unspecified | Unspecified |
20	20
21		-Issue #67 therefore remains open. Its macOS core is substantially implemented,
22		-but closing it would imply cross-platform and modal/parent semantics that Craft
23		-does not yet provide.
	21	+Issue #67 remains open while the portable runtime smoke and the still-unspecified
	22	+modal/parent semantics are reviewed. A green cross-build alone does not prove
	23	+that WebView2 opens and tears down a real window on Windows.
	24	+
	25	+Linux and Windows keep their live native window/webview pairs in
	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.
	28	+Replies go back to the requesting view, and lifecycle events go to the changed
	29	+window plus its named handle's creator. Linux must register its `GtkApplication`
	30	+before constructing the first `GtkApplicationWindow`, because the CLI creates
	31	+that window before entering `g_application_run()`.
24	32
25	33	## Per-window state
26	34
		⋯91 linesShow the 91 lines above this hunk@@ -118,13 +126,12 @@ The next multi-window milestone needs product decisions in addition to code:
118	126	application-level asynchronous source above.
119	127	3. Decide whether Touch Bar should stay primary-window scoped or follow the
120	128	key window with separately owned item definitions and callbacks.
121		-4. Bring Linux and Windows runtime creation, stable handles, sender routing,
122		- lifecycle events and destroy semantics up to the macOS contract. Their
123		- platform backends can create native windows today, but the TypeScript bridge
124		- deliberately reports runtime creation as unsupported outside macOS.
125		-5. Add platform-native integration coverage. Source conformance and pure state
126		- tests defend macOS invariants without requiring a GUI runner, but they do
127		- not substitute for real Windows WebView2 and Linux WebKitGTK lifecycle tests.
	129	+4. Finish advanced Linux/Windows window actions and clarify which are portable
	130	+ versus platform-specific, without conflating close semantics: macOS retains
	131	+ a closed page, while Linux and Windows release it.
	132	+5. Complete platform-native integration coverage. Linux WebKitGTK runs under
	133	+ Xvfb in CI; Windows currently has a cross-build but still needs a real
	134	+ WebView2 lifecycle smoke on a capable Windows runner.
128	135
129	136	## Review checklist
130	137

packages/zig/src/linux.zigmodified+23-2

Changes to packages/zig/src/linux.zig

		⋯15 linesShow the 15 lines above this hunk@@ -16,7 +16,9 @@ const window_reply_target = ;
16	16	// GTK and WebKit C bindings
17	17	pub extern "c" fn gtk_init(argc: ?*c_int, argv: ?*anyopaque) void;
18	18	pub extern "c" fn gtk_application_new(application_id: [*:0]const u8, flags: c_int) ?*anyopaque;
	19	+pub extern "c" fn g_application_register(app: *anyopaque, cancellable: ?*anyopaque, err: ?*?*anyopaque) c_int;
19	20	pub extern "c" fn g_application_run(app: *anyopaque, argc: c_int, argv: [*c][*c]u8) c_int;
	21	+pub extern "c" fn g_object_unref(object: *anyopaque) void;
20	22	pub extern "c" fn gtk_application_window_new(app: *anyopaque) *anyopaque;
21	23	pub extern "c" fn gtk_window_set_title(window: *anyopaque, title: [*:0]const u8) void;
22	24	pub extern "c" fn gtk_window_set_default_size(window: *anyopaque, width: c_int, height: c_int) void;
		⋯494 linesShow the 494 lines above this hunk@@ -517,6 +519,13 @@ fn handleWindowAction(action: []const u8, data: ?[]const u8) !void {
517	519	// Application state
518	520	var app_instance: ?*anyopaque = null;
519	521
	522	+fn onApplicationActivated(_: *anyopaque, _: ?*anyopaque) callconv(.c) void {
	523	+ // The CLI creates and shows its first window before g_application_run().
	524	+ // Activation presents that already-owned window instead of constructing
	525	+ // another one.
	526	+ if (desktop_windows.latest()) |entry| gtk_window_present(@ptrFromInt(entry.window));
	527	+}
	528	+
520	529	pub const WindowStyle = struct {
521	530	frameless: bool = false,
522	531	transparent: bool = false,
		⋯29 linesShow the 29 lines above this hunk@@ -552,7 +561,19 @@ pub const Window = struct {
552	561	// Initialize GTK if not already done
553	562	if (app_instance == null) {
554	563	gtk_init(null, null);
555		- app_instance = gtk_application_new("com.craft.app", 0);
	564	+ const app = gtk_application_new("com.craft.app", 0) orelse return error.ApplicationCreationFailed;
	565	+ if (g_signal_connect_data(app, "activate", @ptrCast(&onApplicationActivated), null, null, 0) == 0) {
	566	+ g_object_unref(app);
	567	+ return error.SignalConnectionFailed;
	568	+ }
	569	+ // GtkApplicationWindow must not be added before the application's
	570	+ // startup signal. Register now because Craft creates its first
	571	+ // window before entering g_application_run().
	572	+ if (g_application_register(app, null, null) == 0) {
	573	+ g_object_unref(app);
	574	+ return error.ApplicationRegistrationFailed;
	575	+ }
	576	+ app_instance = app;
556	577	}
557	578
558	579	const window = gtk_application_window_new(app_instance.?);
		⋯199 linesShow the 199 lines above this hunk@@ -758,7 +779,7 @@ pub const Window = struct {
758	779	pub const App = struct {
759	780	pub fn run() !void {
760	781	if (app_instance) |app| {
761		- _ = g_application_run(app, 0, undefined);
	782	+ _ = g_application_run(app, 0, null);
762	783	}
763	784	}
764	785

scripts/verify-linux-multi-window.tsmodified+3-1

Changes to scripts/verify-linux-multi-window.ts

		⋯89 linesShow the 89 lines above this hunk@@ -90,6 +90,7 @@ const childPage = `<!doctype html><script>
90	90	</script>`
91	91
92	92	const steps = new Set<string>()
	93	+const requests: string[] = []
93	94	let resolveDone!: () => void
94	95	let rejectDone!: (error: Error) => void
95	96	const done = new Promise<void>((resolve, reject) => {
		⋯2 linesShow the 2 lines above this hunk@@ -98,6 +99,7 @@ const done = new Promise<void>((resolve, reject) => {
98	99	})
99	100	const server = createServer((request, response) => {
100	101	const url = new URL(request.url ?? '/', 'http://127.0.0.1')
	102	+ requests.push(url.pathname)
101	103	if (url.pathname === '/main' || url.pathname === '/child') {
102	104	response.setHeader('content-type', 'text/html; charset=utf-8')
103	105	response.end(url.pathname === '/main' ? mainPage : childPage)
		⋯41 linesShow the 41 lines above this hunk@@ -145,7 +147,7 @@ try {
145	147	console.log(`Linux multi-window smoke passed: ${[...steps].join(', ')}`)
146	148	}
147	149	catch (error) {
148		- throw new Error(`${String(error)}\nCraft output:\n${output}`)
	150	+ throw new Error(`${String(error)}\nHTTP requests: ${requests.join(', ')}\nCraft output:\n${output}`)
149	151	}
150	152	finally {
151	153	clearTimeout(timer)