infra: add logging wrapping

Resolves issues with gcp cloud logging quirks such as field names

go/internal/handler/metadata.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"io"
-	"log/slog"
 	"net"
 	"net/http"
 	"net/url"
@@ -12,6 +11,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/flowy-live/llink/internal/utils/flog"
 )
 
 // LinkMetadata mirrors the TS shape in `js/desktop/src/lib/link-metadata.ts`.
@@ -63,7 +64,7 @@ func (h *Handler) GetLinkMetadata(w http.ResponseWriter, r *http.Request) {
 
 	meta, err := fetchLinkMetadata(r.Context(), parsed)
 	if err != nil {
-		slog.Warn("link metadata fetch failed", "url", raw, "error", err)
+		flog.Warn("link metadata fetch failed", "url", raw, "error", err)
 		writeJSON(w, nil)
 		return
 	}