feat(bookstack-api-2x5): implement SearchService

Implement full-text search across all Bookstack content types with
pagination support via ListOptions. Add mock server tests.

search.go

@@ -1,15 +1,34 @@
 package bookstack
 
-import "context"
+import (
+	"context"
+	"net/url"
+	"strconv"
+)
 
 // SearchService handles search operations.
 type SearchService struct {
 	client *Client
 }
 
-// Search performs a search query across all content types.
-// TODO: Implement API call to GET /api/search
+// Search performs a full-text search query across all content types.
+// The query parameter uses Bookstack's search syntax.
 func (s *SearchService) Search(ctx context.Context, query string, opts *ListOptions) ([]SearchResult, error) {
-	// Placeholder for future implementation
-	return nil, nil
+	v := url.Values{}
+	v.Set("query", query)
+	if opts != nil {
+		if opts.Count > 0 {
+			v.Set("count", strconv.Itoa(opts.Count))
+		}
+		if opts.Offset > 0 {
+			v.Set("offset", strconv.Itoa(opts.Offset))
+		}
+	}
+
+	var resp listResponse[SearchResult]
+	err := s.client.do(ctx, "GET", "/api/search?"+v.Encode(), nil, &resp)
+	if err != nil {
+		return nil, err
+	}
+	return resp.Data, nil
 }