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/browser/login.go

@@ -0,0 +1,102 @@
+package browser
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"time"
+
+	"github.com/chromedp/cdproto/network"
+	"github.com/chromedp/chromedp"
+
+	"git.davoryn.de/calic/claude-statusline/internal/config"
+)
+
+// LoginAndGetSessionKey opens a browser window for the user to log in to
+// claude.ai and extracts the httpOnly sessionKey cookie via DevTools protocol.
+// The browser uses a persistent profile so the user only needs to log in once.
+// Returns the session key or an error (e.g. timeout after 2 minutes).
+func LoginAndGetSessionKey() (string, error) {
+	execPath := findBrowserExec()
+
+	profileDir := filepath.Join(config.ConfigDir(), "browser-profile")
+	if err := os.MkdirAll(profileDir, 0o755); err != nil {
+		return "", fmt.Errorf("create browser profile dir: %w", err)
+	}
+
+	opts := append(chromedp.DefaultExecAllocatorOptions[:],
+		chromedp.Flag("headless", false),
+		chromedp.UserDataDir(profileDir),
+	)
+	if execPath != "" {
+		opts = append(opts, chromedp.ExecPath(execPath))
+	}
+
+	allocCtx, allocCancel := chromedp.NewExecAllocator(context.Background(), opts...)
+	defer allocCancel()
+
+	ctx, cancel := chromedp.NewContext(allocCtx)
+	defer cancel()
+
+	// Navigate to login page
+	if err := chromedp.Run(ctx, chromedp.Navigate("https://claude.ai/login")); err != nil {
+		return "", fmt.Errorf("navigate to login: %w", err)
+	}
+
+	// Poll for the sessionKey cookie (httpOnly, so only accessible via DevTools)
+	deadline := time.Now().Add(2 * time.Minute)
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			if time.Now().After(deadline) {
+				return "", fmt.Errorf("login timed out after 2 minutes")
+			}
+
+			var cookies []*network.Cookie
+			if err := chromedp.Run(ctx, chromedp.ActionFunc(func(ctx context.Context) error {
+				var err error
+				cookies, err = network.GetCookies().Do(ctx)
+				return err
+			})); err != nil {
+				// Browser may have been closed by user
+				return "", fmt.Errorf("get cookies: %w", err)
+			}
+
+			for _, c := range cookies {
+				if c.Name == "sessionKey" && (c.Domain == ".claude.ai" || c.Domain == "claude.ai") {
+					key := c.Value
+					if err := config.SetSessionKey(key); err != nil {
+						return "", fmt.Errorf("save session key: %w", err)
+					}
+					// Use chromedp.Cancel to close gracefully (flushes cookies to profile)
+					cancel()
+					return key, nil
+				}
+			}
+		}
+	}
+}
+
+// findBrowserExec returns the path to a Chromium-based browser, or "" to let
+// chromedp use its default detection (Chrome/Chromium on PATH).
+func findBrowserExec() string {
+	if runtime.GOOS == "windows" {
+		// Prefer Edge (pre-installed on Windows 10+)
+		candidates := []string{
+			filepath.Join(os.Getenv("ProgramFiles(x86)"), "Microsoft", "Edge", "Application", "msedge.exe"),
+			filepath.Join(os.Getenv("ProgramFiles"), "Microsoft", "Edge", "Application", "msedge.exe"),
+		}
+		for _, p := range candidates {
+			if _, err := os.Stat(p); err == nil {
+				return p
+			}
+		}
+	}
+	// On Linux/macOS, chromedp auto-detects Chrome/Chromium
+	return ""
+}