Add native self-hosted instance connection to fluxer_desktop

Trimmed monorepo checkout (fluxer_desktop + packages/voice_engine_v2 +
tools/ci) with a "Connect to a Different Server" menu item and popout
that lets the desktop app switch to any self-hosted Fluxer instance,
plus fixes for well-known discovery on single-domain self-hosted
deployments and a false-positive ERR_ABORTED on same-origin client
redirects during the switch. Defaults to chat.fluxr.chat and uses an
isolated userData directory from the official build.

fluxer_desktop/native/linux-input-hook/index.d.ts

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+export type InputEvent =
+	| {
+			type: 'keydown' | 'keyup';
+			keycode: number;
+			keyName: string;
+			ctrlKey: boolean;
+			altKey: boolean;
+			shiftKey: boolean;
+			metaKey: boolean;
+	  }
+	| {
+			type: 'mousedown' | 'mouseup';
+			button: number;
+			ctrlKey: boolean;
+			altKey: boolean;
+			shiftKey: boolean;
+			metaKey: boolean;
+			x?: number;
+			y?: number;
+	  }
+	| {
+			type: 'mousemove';
+			x: number;
+			y: number;
+			ctrlKey: boolean;
+			altKey: boolean;
+			shiftKey: boolean;
+			metaKey: boolean;
+	  }
+	| {
+			type: 'wheel';
+			x?: number;
+			y?: number;
+			deltaX: number;
+			deltaY: number;
+			ctrlKey: boolean;
+			altKey: boolean;
+			shiftKey: boolean;
+			metaKey: boolean;
+	  };
+
+export declare class InputHook {
+	constructor(callback: (event: InputEvent) => void);
+
+	start(): void;
+
+	stop(): void;
+}
+
+export declare function isAvailable(): boolean;
+
+export declare const loadError: Error | null;