Initial commit: Azure DevOps TUI client

A terminal-based user interface for browsing and managing Azure DevOps
work items. Features include:

- Browse work items with filtering by area, iteration, state, and type
- View work item details with markdown rendering
- Open work items in browser
- Create git branches from work items
- Update work item state
- Keyboard-driven navigation

🤖 Generated with [Claude Code](https://claude.ai/claude-code)

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

pkg/browser/open.go

@@ -0,0 +1,26 @@
+package browser
+
+import (
+	"os/exec"
+	"runtime"
+)
+
+// Open opens the specified URL in the default browser
+func Open(url string) error {
+	var cmd string
+	var args []string
+
+	switch runtime.GOOS {
+	case "windows":
+		cmd = "rundll32"
+		args = []string{"url.dll,FileProtocolHandler", url}
+	case "darwin":
+		cmd = "open"
+		args = []string{url}
+	default: // linux and others
+		cmd = "xdg-open"
+		args = []string{url}
+	}
+
+	return exec.Command(cmd, args...).Start()
+}