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/encoder-ring/benches/ring.rs

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use std::hint::black_box;
+
+use criterion::{Criterion, criterion_group, criterion_main};
+use fluxer_encoder_ring::{CpuMemcpyBackend, EncoderInputRing, TextureFormat};
+
+fn bench_submit_poll_release_cycle(c: &mut Criterion) {
+    let mut group = c.benchmark_group("encoder_input_ring");
+    group.sample_size(60);
+    group.bench_function("submit_poll_release_1080p_nv12", |b| {
+        let mut ring = EncoderInputRing::new(CpuMemcpyBackend::new());
+        ring.initialise(1920, 1080, TextureFormat::Nv12)
+            .expect("init");
+        b.iter(|| {
+            ring.submit(|_h| {}).expect("submit");
+            let ready = ring.poll_next_ready().expect("ready");
+            black_box(&ready);
+            ring.release_completed(ready).expect("release");
+        });
+    });
+    group.finish();
+}
+
+fn bench_submit_only_drained_after(c: &mut Criterion) {
+    let mut group = c.benchmark_group("encoder_input_ring");
+    group.sample_size(60);
+    group.bench_function("submit_then_drain_eight_1080p_nv12", |b| {
+        b.iter(|| {
+            let mut ring = EncoderInputRing::new(CpuMemcpyBackend::new());
+            ring.initialise(1920, 1080, TextureFormat::Nv12)
+                .expect("init");
+            for _ in 0..8 {
+                ring.submit(|_h| {}).expect("submit");
+            }
+            for _ in 0..8 {
+                let ready = ring.poll_next_ready().expect("ready");
+                ring.release_completed(ready).expect("release");
+            }
+            black_box(ring.metrics());
+        });
+    });
+    group.finish();
+}
+
+criterion_group!(
+    benches,
+    bench_submit_poll_release_cycle,
+    bench_submit_only_drained_after
+);
+criterion_main!(benches);