Atomize actors and centralize knowledge of WindowServer state

[tmandry]

Significant refactor of the actors. This centralizes knowledge of window server state in the WindowServer actor, including the current space, screen configuration, and windows visible on screen.

This refactoring is intended as a lead up to supporting #65. It's also useful in its own right in that it gives each actor a clearer scope and set of responsibilities.

[tmandry]

• New actors should have tests; we can mock out their system calls with #[cfg(test)]
• App actor can remove its dependence on sys::window_server::get_windows: Just call this in WindowServer

[tmandry]

/gemini review

[Copilot]

Pull request overview

Copilot reviewed 16 out of 17 changed files in this pull request and generated 4 comments.

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[gemini-code-assist]

Code Review

This pull request introduces a major architectural refactor by adding a SpaceManager actor and restructuring the WindowServer. The SpaceManager now centralizes space enablement logic, global state management (login window, expose mode), and hotkey activation, which were previously handled by the WmController. The WindowServer has been split into a main-thread SkylightWatcher for system events and an off-main-thread actor that enriches application events with window server metadata. Additionally, WindowId now utilizes a bitmask to differentiate between system and manual indices, and the Reactor has been updated to use WindowsOnScreen snapshots for more reliable state synchronization. Review feedback suggests grouping the extensive list of channel arguments in Reactor::spawn into a struct to improve readability and maintainability.

[gemini-code-assist]

This function has a large number of arguments (16), which can make it hard to use and maintain. While clippy::too_many_arguments is suppressed, it would be beneficial to group related arguments into a struct. For instance, all the actor channels could be grouped into a single Channels struct. This would improve readability and make the function signature more manageable.

Example:

struct ActorChannels {
    mouse_tx: mouse::Sender,
    status_tx: status::Sender,
    group_indicators_tx: group_bars::Sender,
    reactor_tx: reactor::Sender,
    reactor_rx: reactor::Receiver,
    wm_tx: wm_controller::Sender,
    ws_tx: window_server::Sender,
    ws_rx: window_server::Receiver,
    sm_tx: space_manager::Sender,
    sm_rx: space_manager::Receiver,
    skylight_tx: window_server::SkylightSender,
}

// ...

pub fn spawn(
    config: Arc<Config>,
    one_space: bool,
    layout: LayoutManager,
    record: Record,
    channels: ActorChannels,
) {
    // ...
}

[Copilot]

Pull request overview

Copilot reviewed 16 out of 17 changed files in this pull request and generated 2 comments.

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[Copilot]

Handling Event::WindowsOnScreenUpdated only updates visible_windows/window_server_info, but it does not trigger any follow-up to refresh accessibility-visible windows (e.g. Request::GetVisibleWindows / on_windows_discovered). As a result, visibility-only changes (like minimize/unminimize, which now emit WindowVisibilityChanged → WindowsOnScreenUpdated) won't update the layout until the next space change. Consider requesting GetVisibleWindows for the affected app (when pid is Some) or calling update_visible_windows() after applying the snapshot.

Suggested change

	Event::WindowsOnScreenUpdated { pid, on_screen } => match pid {
	Some(_) => self.update_partial_window_server_info(on_screen),
	None => self.update_complete_window_server_info(on_screen),
	},
	Event::WindowsOnScreenUpdated { pid, on_screen } => {
	match pid {
	Some(_) => self.update_partial_window_server_info(on_screen),
	None => self.update_complete_window_server_info(on_screen),
	}
	self.update_visible_windows();
	}

[tmandry]

I've been using this for a few days without running into regressions. Should be ready to merge.