feat: initial commit — unarr CLI

Search, inspect, stream, and download torrents from the terminal.
Replaces the entire *arr stack with a single binary.

internal/engine/stream_player.go

@@ -0,0 +1,74 @@
+package engine
+
+import (
+	"fmt"
+	"os/exec"
+	"runtime"
+)
+
+// OpenPlayer attempts to open a media player with the given stream URL.
+// Returns the player name and the running command.
+// If override is set, it uses that command directly.
+func OpenPlayer(url, override string) (string, *exec.Cmd, error) {
+	if override != "" {
+		cmd := exec.Command(override, url)
+		if err := cmd.Start(); err != nil {
+			return override, nil, fmt.Errorf("start %s: %w", override, err)
+		}
+		return override, cmd, nil
+	}
+
+	// Try mpv first (best streaming support)
+	if path, err := exec.LookPath("mpv"); err == nil {
+		cmd := exec.Command(path, "--no-terminal", url)
+		if err := cmd.Start(); err == nil {
+			return "mpv", cmd, nil
+		}
+	}
+
+	// Try VLC
+	if path, err := exec.LookPath("vlc"); err == nil {
+		cmd := exec.Command(path, url)
+		if err := cmd.Start(); err == nil {
+			return "vlc", cmd, nil
+		}
+	}
+
+	// Try cvlc (VLC headless)
+	if path, err := exec.LookPath("cvlc"); err == nil {
+		cmd := exec.Command(path, url)
+		if err := cmd.Start(); err == nil {
+			return "vlc (headless)", cmd, nil
+		}
+	}
+
+	// Browser fallback
+	name, cmd, err := openBrowser(url)
+	if err != nil {
+		return "", nil, fmt.Errorf("no player found: install mpv or vlc, or open %s manually", url)
+	}
+	return name, cmd, nil
+}
+
+func openBrowser(url string) (string, *exec.Cmd, error) {
+	switch runtime.GOOS {
+	case "linux":
+		if path, err := exec.LookPath("xdg-open"); err == nil {
+			cmd := exec.Command(path, url)
+			if err := cmd.Start(); err == nil {
+				return "browser", cmd, nil
+			}
+		}
+	case "darwin":
+		cmd := exec.Command("/usr/bin/open", url)
+		if err := cmd.Start(); err == nil {
+			return "browser", cmd, nil
+		}
+	case "windows":
+		cmd := exec.Command("rundll32", "url.dll,FileProtocolHandler", url)
+		if err := cmd.Start(); err == nil {
+			return "browser", cmd, nil
+		}
+	}
+	return "", nil, fmt.Errorf("no browser opener found")
+}