Remove standalone fetcher, add setup tool with install/uninstall workflow

Drop claude-fetcher binary and cron job — the widget's built-in
BackgroundFetcher is the sole fetcher now. Add cmd/setup with cross-platform
install and uninstall (--uninstall): kills widget, removes binaries + autostart,
cleans Claude Code statusline setting, optionally removes config dir.

Also includes: browser-based login (chromedp), ICO wrapper for Windows tray
icon, and reduced icon size (64px).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/tray/tray.go

@@ -2,11 +2,13 @@ package tray
 
 import (
 	"fmt"
-	"os/exec"
-	"runtime"
+	"log"
+	"os"
+	"path/filepath"
 	"sync"
 
 	"fyne.io/systray"
+	"git.davoryn.de/calic/claude-statusline/internal/browser"
 	"git.davoryn.de/calic/claude-statusline/internal/config"
 	"git.davoryn.de/calic/claude-statusline/internal/fetcher"
 	"git.davoryn.de/calic/claude-statusline/internal/renderer"
@@ -49,8 +51,11 @@ func (a *App) onReady() {
 	systray.SetTooltip("Claude Usage: loading...")
 
 	// Set initial icon (0%)
-	if iconData, err := renderer.RenderIconPNG(0); err == nil {
+	iconData, err := renderer.RenderIconForTray(0)
+	log.Printf("initial icon: %d bytes, render err=%v", len(iconData), err)
+	if err == nil {
 		systray.SetIcon(iconData)
+		log.Println("SetIcon called (initial)")
 	}
 
 	// Usage display items (non-clickable info)
@@ -82,8 +87,9 @@ func (a *App) onReady() {
 		a.menuItems.intervalRadio = append(a.menuItems.intervalRadio, item)
 	}
 
-	// Session key
-	mSessionKey := systray.AddMenuItem("Session Key...", "Open session key config file")
+	// Login / logout
+	mLogin := systray.AddMenuItem("Login in Browser", "Open browser to log in to claude.ai")
+	mLogout := systray.AddMenuItem("Logout", "Clear session key and browser profile")
 
 	systray.AddSeparator()
 	mQuit := systray.AddMenuItem("Quit", "Exit Claude Usage Widget")
@@ -98,8 +104,10 @@ func (a *App) onReady() {
 			select {
 			case <-mRefresh.ClickedCh:
 				a.bf.Refresh()
-			case <-mSessionKey.ClickedCh:
-				a.openSessionKeyFile()
+			case <-mLogin.ClickedCh:
+				go a.doLogin()
+			case <-mLogout.ClickedCh:
+				a.doLogout()
 			case <-mQuit.ClickedCh:
 				systray.Quit()
 				return
@@ -133,8 +141,12 @@ func (a *App) onUsageUpdate(data fetcher.ParsedUsage) {
 	if data.Error == "" {
 		pct = data.FiveHourPct
 	}
-	if iconData, err := renderer.RenderIconPNG(pct); err == nil {
+	log.Printf("onUsageUpdate: pct=%d, error=%q", pct, data.Error)
+	if iconData, err := renderer.RenderIconForTray(pct); err == nil {
 		systray.SetIcon(iconData)
+		log.Printf("SetIcon called (pct=%d, %d bytes)", pct, len(iconData))
+	} else {
+		log.Printf("RenderIconPNG error: %v", err)
 	}
 
 	// Update tooltip
@@ -200,16 +212,19 @@ func (a *App) setInterval(idx int) {
 	a.bf.SetInterval(intervals[idx].seconds)
 }
 
-func (a *App) openSessionKeyFile() {
-	path := config.SessionKeyPath()
-	var cmd *exec.Cmd
-	switch runtime.GOOS {
-	case "windows":
-		cmd = exec.Command("notepad", path)
-	case "darwin":
-		cmd = exec.Command("open", "-t", path)
-	default:
-		cmd = exec.Command("xdg-open", path)
+func (a *App) doLogin() {
+	systray.SetTooltip("Claude Usage: logging in...")
+	_, err := browser.LoginAndGetSessionKey()
+	if err != nil {
+		systray.SetTooltip(fmt.Sprintf("Claude Usage: login failed — %s", err))
+		return
 	}
-	_ = cmd.Start()
+	a.bf.Refresh()
+}
+
+func (a *App) doLogout() {
+	_ = os.Remove(config.SessionKeyPath())
+	profileDir := filepath.Join(config.ConfigDir(), "browser-profile")
+	_ = os.RemoveAll(profileDir)
+	a.bf.Refresh()
 }