Session 3: Radarr/Sonarr/Lidarr clients with add-on-search

Adds internal/arr with a shared HTTP layer and per-service clients that
look up candidates and POST the chosen one back with monitored=true and
search-on-add enabled. Lidarr requires metadata_profile_id, now part of
ArrConfig and validated when lidarr is set.

internal/arr/radarr.go

@@ -0,0 +1,60 @@
+package arr
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"bellhop/internal/config"
+)
+
+// Radarr drives a Radarr v3 instance.
+type Radarr struct {
+	h                *httpClient
+	qualityProfileID int
+	rootFolder       string
+}
+
+func NewRadarr(cfg *config.ArrConfig) *Radarr {
+	return &Radarr{
+		h:                newHTTP(cfg.URL, cfg.APIKey),
+		qualityProfileID: cfg.QualityProfileID,
+		rootFolder:       cfg.RootFolder,
+	}
+}
+
+func (r *Radarr) Search(ctx context.Context, term string) ([]Result, error) {
+	body, err := r.h.get(ctx, "/api/v3/movie/lookup", map[string]string{"term": term})
+	if err != nil {
+		return nil, err
+	}
+	return parseLookup(body, "title")
+}
+
+func (r *Radarr) Add(ctx context.Context, res Result) error {
+	if len(res.raw) == 0 {
+		return fmt.Errorf("radarr: empty result")
+	}
+	body, err := buildAddBody(res.raw, map[string]any{
+		"qualityProfileId": r.qualityProfileID,
+		"rootFolderPath":   r.rootFolder,
+		"monitored":        true,
+		"addOptions": map[string]any{
+			"searchForMovie": true,
+		},
+	})
+	if err != nil {
+		return err
+	}
+	_, err = r.h.post(ctx, "/api/v3/movie", body)
+	return err
+}
+
+// compile-time interface check
+var _ Client = (*Radarr)(nil)
+
+// makeResult is a tiny helper used by tests in this package to construct a
+// Result from arbitrary JSON without going through the network.
+func makeResult(title string, year int, raw string) Result {
+	return Result{Title: title, Year: year, raw: json.RawMessage(raw)}
+}