feat: Windows NSIS installer, embedded icons, GUI auto-launch backend

- Add package/installer.nsi (Full/Server/Client) and toolchain.nsi
- Embed icon.ico (rounded corners) into homed.exe/waiter.exe via .syso
- GUI auto-launches homed.exe from parent dir (Windows only)
- GUI fallback connections.json from app resource dir
- Add initconfig command for config.db seeding
- Replace waiter rawmode* with raw_{unix,windows,other}.go
- Fix .gitignore: /homed instead of homed, add login.json
- Update icon.svg with rounded rect, new mascot.svg

cmd/waiter/raw_unix.go

@@ -0,0 +1,43 @@
+//go:build linux
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func setRawMode(fd int) (func(), error) {
+	if fd == 0 {
+		fd = int(os.Stdin.Fd())
+	}
+	if !isTerminal(fd) {
+		return func() {}, nil
+	}
+	var oldState syscall.Termios
+	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), syscall.TCGETS, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); err != 0 {
+		return func() {}, fmt.Errorf("tcgets: %v", err)
+	}
+	newState := oldState
+	newState.Iflag &^= syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK | syscall.ISTRIP | syscall.INLCR | syscall.IGNCR | syscall.ICRNL | syscall.IXON
+	newState.Oflag &^= syscall.OPOST
+	newState.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG | syscall.IEXTEN
+	newState.Cflag &^= syscall.CSIZE | syscall.PARENB
+	newState.Cflag |= syscall.CS8
+	newState.Cc[syscall.VMIN] = 1
+	newState.Cc[syscall.VTIME] = 0
+	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), syscall.TCSETS, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
+		return func() {}, fmt.Errorf("tcset: %v", err)
+	}
+	return func() {
+		syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), syscall.TCSETS, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
+	}, nil
+}
+
+func isTerminal(fd int) bool {
+	var t syscall.Termios
+	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), syscall.TCGETS, uintptr(unsafe.Pointer(&t)), 0, 0, 0)
+	return err == 0
+}