Hide native title bar, add custom frameless window controls

- Remove WS_CAPTION via SetWindowLong to hide native Windows title bar
- Keep WS_THICKFRAME for window resizing from edges
- Add custom Win11-style window control buttons (minimize, maximize, close)
- Close button turns red on hover (#c42b1c) matching Windows 11
- Title bar is draggable via -webkit-app-region: drag
- Bind windowMinimize/windowMaximize/windowClose Go functions to JS
- Center system status indicator in title bar

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

main.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"os/signal"
 	"syscall"
+	"unsafe"
 
 	"github.com/jchv/go-webview2"
 	"github.com/mumur/driver-booster/internal/bridge"
@@ -22,6 +23,51 @@ import (
 //go:embed ui/*
 var uiFS embed.FS
 
+var (
+	user32            = syscall.NewLazyDLL("user32.dll")
+	procGetWindowLong = user32.NewProc("GetWindowLongW")
+	procSetWindowLong = user32.NewProc("SetWindowLongW")
+	procSetWindowPos  = user32.NewProc("SetWindowPos")
+	procPostMessage   = user32.NewProc("PostMessageW")
+	procShowWindow    = user32.NewProc("ShowWindow")
+)
+
+const (
+	gwlStyle     = -16
+	wsCaption    = 0x00C00000
+	wsSysMenu    = 0x00080000
+	wsThickFrame = 0x00040000
+	wsMinBox     = 0x00020000
+	wsMaxBox     = 0x00010000
+	wsVisible    = 0x10000000
+	wsPopup      = 0x80000000
+
+	swpFrameChanged = 0x0020
+	swpNoMove       = 0x0002
+	swpNoSize       = 0x0001
+	swpNoZOrder     = 0x0004
+
+	wmSysCommand = 0x0112
+	scMinimize   = 0xF020
+	scMaximize   = 0xF030
+	scRestore    = 0xF120
+	scClose      = 0xF060
+
+	swMaximize = 3
+	swRestore  = 9
+)
+
+func removeWindowFrame(hwnd uintptr) {
+	gwlStyleUintptr := uintptr(0xFFFFFFF0) // GWL_STYLE = -16 as unsigned
+	style, _, _ := procGetWindowLong.Call(hwnd, gwlStyleUintptr)
+	// Remove caption (title bar) but keep thick frame (resizable) and min/max boxes
+	newStyle := (style &^ wsCaption) | wsThickFrame | wsMinBox | wsMaxBox
+	procSetWindowLong.Call(hwnd, gwlStyleUintptr, newStyle)
+	// Force redraw frame
+	procSetWindowPos.Call(hwnd, 0, 0, 0, 0, 0,
+		swpFrameChanged|swpNoMove|swpNoSize|swpNoZOrder)
+}
+
 func main() {
 	// Start embedded HTTP server for UI assets
 	uiContent, err := fs.Sub(uiFS, "ui")
@@ -74,6 +120,24 @@ func main() {
 	}
 	defer w.Destroy()
 
+	// Remove native title bar to use our custom one
+	hwnd := uintptr(unsafe.Pointer(w.Window()))
+	removeWindowFrame(hwnd)
+
+	// Bind window control functions for custom title bar buttons
+	w.Bind("windowMinimize", func() {
+		procPostMessage.Call(hwnd, wmSysCommand, scMinimize, 0)
+	})
+	w.Bind("windowMaximize", func() {
+		procPostMessage.Call(hwnd, wmSysCommand, scMaximize, 0)
+	})
+	w.Bind("windowRestore", func() {
+		procPostMessage.Call(hwnd, wmSysCommand, scRestore, 0)
+	})
+	w.Bind("windowClose", func() {
+		procPostMessage.Call(hwnd, wmSysCommand, scClose, 0)
+	})
+
 	// Bind Go functions to JS
 	w.Bind("goGetSysInfo", func() string {
 		info := b.SysInfo.Collect()