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/screen-frame-bus/benches/frame_pool.rs

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use std::hint::black_box;
+
+use criterion::{Criterion, criterion_group, criterion_main};
+use fluxer_screen_frame_bus::frame_pool::{CpuFrameBuilder, FRAME_BYTES_MAX};
+
+fn bench_acquire_release_cpu_1080p_rgba(c: &mut Criterion) {
+    assert_eq!(FRAME_BYTES_MAX, 1920 * 1080 * 4);
+    let pool = CpuFrameBuilder::build_pool(FRAME_BYTES_MAX)
+        .expect("pool must allocate at construction time");
+    assert!(pool.capacity() > 0);
+
+    c.bench_function("frame_pool/acquire_release/cpu_1080p_rgba", |b| {
+        b.iter(|| {
+            let frame = pool
+                .try_acquire()
+                .expect("steady state single-threaded never starves");
+            black_box(frame.slot_index());
+        });
+    });
+    assert_eq!(pool.currently_in_flight(), 0);
+}
+
+criterion_group!(benches, bench_acquire_release_cpu_1080p_rgba);
+criterion_main!(benches);