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/webrtc-sys/.clang-format

@@ -0,0 +1,24 @@
+# Using the same .clang-format as libwebrtc
+# https://github.com/webrtc-sdk/webrtc/blob/m104_release/.clang-format
+BasedOnStyle: Chromium
+---
+Language: Java
+BasedOnStyle: Google
+---
+Language: ObjC
+BasedOnStyle: Google
+BinPackParameters: false
+BinPackArguments: false
+ColumnLimit: 100
+ObjCBlockIndentWidth: 2
+AllowAllParametersOfDeclarationOnNextLine: true
+AlignOperands: false
+AlwaysBreakBeforeMultilineStrings: false
+AllowShortFunctionsOnASingleLine: Inline
+BreakBeforeTernaryOperators: false
+IndentWrappedFunctionNames: true
+ContinuationIndentWidth: 4
+ObjCSpaceBeforeProtocolList: true
+---
+Language: Cpp
+IncludeBlocks: Regroup