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-audio-capture/index.d.ts

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {EventEmitter} from 'node:events';
+
+export interface JsRoutingRule {
+	include?: Array<Record<string, string>>;
+	exclude?: Array<Record<string, string>>;
+	workaround?: Array<Record<string, string>>;
+	ignoreDevices?: boolean;
+	onlySpeakers?: boolean;
+	onlyDefaultSpeakers?: boolean;
+}
+
+export interface AudioFrame {
+	samples: Float32Array;
+	sampleRate: number;
+	channels: number;
+	timestampUs: number;
+}
+
+export interface NativeAudioFrame {
+	samples: ArrayBuffer;
+	sampleRate: number;
+	channels: number;
+	timestampUs: number;
+}
+
+export interface RoutingGraphNode {
+	id: number;
+	props: Record<string, string>;
+}
+
+export interface RoutingGraphPort {
+	id: number;
+	nodeId: number;
+	direction: string;
+	channel: string;
+	props: Record<string, string>;
+}
+
+export interface RoutingGraphLink {
+	outputNodeId: number;
+	outputPortId: number;
+	inputNodeId: number;
+	inputPortId: number;
+	owned: boolean;
+	passive: boolean;
+}
+
+export interface RoutingGraph {
+	backend: 'pipewire' | 'none' | string;
+	nodes: Array<RoutingGraphNode>;
+	ports: Array<RoutingGraphPort>;
+	ownedLinks: Array<RoutingGraphLink>;
+}
+
+export declare function pipeWireAvailable(): boolean;
+
+export declare function audioBackend(): 'pipewire' | 'none';
+
+export declare class AudioBridge {
+	constructor();
+
+	inventory(fields?: Array<string> | undefined | null): Array<Record<string, string>>;
+
+	routingGraph(): RoutingGraph;
+
+	apply(rule: JsRoutingRule): boolean;
+
+	release(): void;
+
+	backend(): 'pipewire' | 'none';
+}
+
+export declare class DirectAudioCapture {
+	constructor();
+
+	start(rule: JsRoutingRule): boolean;
+
+	setRule(rule: JsRoutingRule): boolean;
+
+	setLifecycleCallback(callback: (type: string, message: string) => void): void;
+
+	read(): NativeAudioFrame | null;
+
+	routingGraph(): RoutingGraph;
+
+	stop(): void;
+}
+
+export declare class AudioMixRuntimeHandle {
+	constructor(sourceCount: number);
+
+	static boundToDirectCapture(capture: DirectAudioCapture): AudioMixRuntimeHandle;
+
+	sourceCount(): number;
+
+	tick(tickAtNs?: number | null): number;
+
+	markPushedTotal(): number;
+
+	dispose(): void;
+}
+
+interface ProcessLoopbackEvents {
+	on(event: 'frame', listener: (frame: AudioFrame) => void): this;
+	on(event: 'error', listener: (error: Error) => void): this;
+	on(event: 'closed', listener: () => void): this;
+	on(event: 'diagnostic', listener: (message: string) => void): this;
+	removeListener(event: 'frame', listener: (frame: AudioFrame) => void): this;
+	removeListener(event: 'error', listener: (error: Error) => void): this;
+	removeListener(event: 'closed', listener: () => void): this;
+	removeListener(event: 'diagnostic', listener: (message: string) => void): this;
+}
+
+export declare class ProcessLoopback extends EventEmitter implements ProcessLoopbackEvents {
+	constructor(targetPid: number, options?: {includeProcessTree?: boolean; ignoreDevices?: boolean});
+
+	constructor(options: {linuxRule: JsRoutingRule});
+
+	start(): void;
+
+	routingGraph(): RoutingGraph | null;
+
+	stop(): Promise<void>;
+}