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/webrtc-sender/vendor/tract-linalg-0.23.1/benches/sigmoid.rs

@@ -0,0 +1,34 @@
+#[macro_use]
+extern crate criterion;
+extern crate tract_linalg;
+use criterion::Criterion;
+
+fn ssigmoid(c: &mut Criterion, n: usize) {
+    c.bench_function(&format!("ssigmoid_tract_{n}"), move |be| {
+        let mut s = (0..n).map(|i| i as f32 / 10.0).collect::<Vec<f32>>();
+        let op = &(tract_linalg::ops().sigmoid_f32)();
+        be.iter(|| op.run(&mut s));
+    });
+}
+
+#[inline(never)]
+fn rust_sigmoid(x: &mut [f32]) {
+    for v in x {
+        *v = 1.0 / (1.0 + (-*v).exp());
+    }
+}
+
+fn ssigmoid_scalar(c: &mut Criterion, n: usize) {
+    c.bench_function(&format!("ssigmoid_scalar_{n}"), move |be| {
+        let mut s = (0..n).map(|i| i as f32 / 10.0).collect::<Vec<f32>>();
+        be.iter(|| rust_sigmoid(&mut s));
+    });
+}
+
+fn bs(c: &mut Criterion) {
+    ssigmoid(c, 1024);
+    ssigmoid_scalar(c, 1024);
+}
+
+criterion_group!(benches, bs);
+criterion_main!(benches);