Add library view and series drill-down (M8)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/arr/update.go

@@ -0,0 +1,55 @@
+package arr
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+)
+
+// Update reads <path>/<id>, lets mutate change the raw JSON object and PUTs it
+// back. Working on raw fields keeps everything the client does not model
+// (Radarr and Sonarr replace the whole resource on PUT).
+func (c *Client) Update(ctx context.Context, path string, id int, mutate func(obj map[string]json.RawMessage) error) error {
+	p := path + "/" + strconv.Itoa(id)
+	var obj map[string]json.RawMessage
+	if err := c.Do(ctx, http.MethodGet, p, nil, nil, &obj); err != nil {
+		return err
+	}
+	if err := mutate(obj); err != nil {
+		return err
+	}
+	return c.Do(ctx, http.MethodPut, p, nil, obj, nil)
+}
+
+// SetBool sets a boolean field of a raw object.
+func SetBool(obj map[string]json.RawMessage, key string, v bool) {
+	obj[key], _ = json.Marshal(v)
+}
+
+// Command posts a command ("MoviesSearch", "SeasonSearch", ...) to /command.
+func (c *Client) Command(ctx context.Context, body map[string]any) error {
+	return c.Do(ctx, http.MethodPost, "command", nil, body, nil)
+}
+
+// SetSeasonMonitored flips one season in a raw series object.
+func SetSeasonMonitored(obj map[string]json.RawMessage, season int, monitored bool) error {
+	var seasons []map[string]json.RawMessage
+	if err := json.Unmarshal(obj["seasons"], &seasons); err != nil {
+		return fmt.Errorf("decoding seasons: %w", err)
+	}
+	found := false
+	for _, s := range seasons {
+		var n int
+		if json.Unmarshal(s["seasonNumber"], &n) == nil && n == season {
+			SetBool(s, "monitored", monitored)
+			found = true
+		}
+	}
+	if !found {
+		return fmt.Errorf("season %d not found", season)
+	}
+	obj["seasons"], _ = json.Marshal(seasons)
+	return nil
+}