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/debrid.go

@@ -0,0 +1,41 @@
+package engine
+
+import (
+	"context"
+	"fmt"
+
+	tc "github.com/torrentclaw/go-client"
+)
+
+// DebridDownloader downloads via debrid services (Real-Debrid, AllDebrid, etc.).
+// Currently a stub — Available() works, Download() returns not-implemented.
+type DebridDownloader struct {
+	apiClient *tc.Client
+}
+
+// NewDebridDownloader creates a debrid downloader stub.
+func NewDebridDownloader(apiClient *tc.Client) *DebridDownloader {
+	return &DebridDownloader{apiClient: apiClient}
+}
+
+func (d *DebridDownloader) Method() DownloadMethod { return MethodDebrid }
+
+func (d *DebridDownloader) Available(ctx context.Context, task *Task) (bool, error) {
+	if d.apiClient == nil {
+		return false, nil
+	}
+	resp, err := d.apiClient.DebridCheckCache(ctx, "", "", []string{task.InfoHash})
+	if err != nil {
+		return false, err
+	}
+	cached, ok := resp.Cached[task.InfoHash]
+	return ok && cached, nil
+}
+
+func (d *DebridDownloader) Download(_ context.Context, _ *Task, _ string, _ chan<- Progress) (*Result, error) {
+	return nil, fmt.Errorf("debrid download not implemented yet (coming in a future release)")
+}
+
+func (d *DebridDownloader) Pause(_ string) error            { return nil }
+func (d *DebridDownloader) Cancel(_ string) error            { return nil }
+func (d *DebridDownloader) Shutdown(_ context.Context) error { return nil }