Suppress verbose vips logging output

Initialize libvips with LogLevelError to prevent info-level messages
from polluting the JSON log stream.

internal/imgcache/processor.go

@@ -6,10 +6,22 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"sync"
 
 	"github.com/davidbyttow/govips/v2/vips"
 )
 
+// vipsOnce ensures vips is initialized exactly once.
+var vipsOnce sync.Once
+
+// initVips initializes libvips with quiet logging.
+func initVips() {
+	vipsOnce.Do(func() {
+		vips.LoggingSettings(nil, vips.LogLevelError)
+		vips.Startup(nil)
+	})
+}
+
 // MaxInputDimension is the maximum allowed width or height for input images.
 // Images larger than this are rejected to prevent DoS via decompression bombs.
 const MaxInputDimension = 8192
@@ -25,6 +37,7 @@ type ImageProcessor struct{}
 
 // NewImageProcessor creates a new image processor.
 func NewImageProcessor() *ImageProcessor {
+	initVips()
 	return &ImageProcessor{}
 }
 

internal/imgcache/processor_test.go

@@ -15,7 +15,7 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	vips.Startup(nil)
+	initVips()
 	code := m.Run()
 	vips.Shutdown()
 	os.Exit(code)