[client/ui] Replace fyne UI with Wails (rename ui-wails to ui)

Removes the legacy fyne-based client/ui implementation and renames the
Wails replacement (client/ui-wails) to take its place at client/ui. Go
imports, frontend bindings, CI workflows, goreleaser configs and the
windows .syso icon path are updated to follow the rename.

client/ui/README.md

@@ -0,0 +1,100 @@
+# NetBird desktop UI (Wails3 + React)
+
+Replaces `client/ui` (Fyne). One binary on Windows / macOS / Linux,
+talks to the NetBird daemon over gRPC, renders a React frontend in a
+WebView.
+
+## Prerequisites
+
+- Go ≥ 1.25, Node ≥ 20, **pnpm** (`corepack enable && corepack prepare pnpm@latest --activate`)
+- `wails3` CLI: `go install github.com/wailsapp/wails/v3/cmd/wails3@latest`
+- `task`: `go install github.com/go-task/task/v3/cmd/task@latest`
+- A running NetBird daemon (default: `unix:///var/run/netbird.sock`,
+  Windows `tcp://127.0.0.1:41731`)
+- Linux only: `libwebkit2gtk-4.1-dev`, `libgtk-3-dev`,
+  `libayatana-appindicator3-dev`
+
+## Develop without rebuilding
+
+```bash
+cd client/ui-wails
+task dev
+```
+
+`task dev` runs Vite (port 9245) + the Go binary + a `*.go` watcher.
+Frontend edits hot-reload instantly. Go edits trigger a rebuild and
+relaunch. Pass daemon flags after `--`:
+
+```bash
+task dev -- --daemon-addr=tcp://127.0.0.1:41731
+```
+
+For pure UI work (no native window, fastest loop):
+
+```bash
+cd frontend && pnpm dev
+```
+
+## Production build
+
+```bash
+task build
+```
+
+Output in `bin/`. Frontend assets are embedded into the binary.
+
+### Cross-compile Windows from Linux
+
+Install the mingw-w64 toolchain once:
+
+```bash
+sudo apt install gcc-mingw-w64-x86-64           # Debian/Ubuntu
+sudo dnf install mingw64-gcc                    # Fedora
+sudo pacman -S mingw-w64-gcc                    # Arch
+```
+
+Then:
+
+```bash
+CGO_ENABLED=1 task windows:build
+```
+
+Produces `bin/netbird-ui.exe`. macOS cross-compile from Linux is not
+supported (signing and notarization need a real Mac).
+
+### Windows console build (logs in the terminal)
+
+Default `windows:build` links the binary as a Windows GUI app, which
+detaches from the launching console — `logrus` output, `fmt.Println`,
+and panics go nowhere visible. To debug tray/event/daemon issues:
+
+```bash
+CGO_ENABLED=1 task windows:build:console
+```
+
+Produces `bin/netbird-ui-console.exe`. Run it from `cmd.exe` /
+PowerShell / Windows Terminal and stdout/stderr land in that
+terminal. Same flag works on a native Windows build (drop the
+`CGO_ENABLED=1` if your toolchain already has it set).
+
+## Regenerating bindings
+
+When a Go service signature changes:
+
+```bash
+wails3 generate bindings
+```
+
+`task dev` does this automatically on `*.go` save.
+
+## Tray icons
+
+Source SVGs live in `assets/svg/` (state.svg + state-macos.svg). After editing
+any SVG, rasterize to the PNGs the Go side embeds:
+
+```bash
+task common:generate:tray:icons
+```
+
+Requires Inkscape. Commit the resulting `assets/*.png` files alongside the
+SVG change so CI doesn't need Inkscape installed.