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/build_resources/entitlements.mac.stable.plist

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- SPDX-License-Identifier: AGPL-3.0-or-later -->
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>com.apple.security.cs.allow-jit</key>
+    <true/>
+    <key>com.apple.security.cs.allow-unsigned-executable-memory</key>
+    <true/>
+    <key>com.apple.security.cs.disable-library-validation</key>
+    <true/>
+    <key>com.apple.security.device.audio-input</key>
+    <true/>
+    <key>com.apple.security.device.microphone</key>
+    <true/>
+    <key>com.apple.security.device.camera</key>
+    <true/>
+    <key>com.apple.security.device.screen-capture</key>
+    <true/>
+    <key>com.apple.security.network.client</key>
+    <true/>
+    <key>com.apple.security.network.server</key>
+    <true/>
+    <key>com.apple.application-identifier</key>
+    <string>3G5837T29K.app.fluxer</string>
+    <key>com.apple.developer.associated-domains</key>
+    <array>
+        <string>webcredentials:fluxer.app</string>
+        <string>webcredentials:web.fluxer.app</string>
+    </array>
+</dict>
+</plist>