s3: Trace SSE chunk metadata through multipart completion and retrieval

Added end-to-end logging to track SSE chunk metadata lifecycle:

**During Multipart Completion (filer_multipart.go)**:
1. Log finalParts chunks BEFORE mkFile - shows SseType and metadata
2. Log versionEntry.Chunks INSIDE mkFile callback - shows if mkFile preserves SSE info
3. Log success after mkFile completes

**During GET Retrieval (s3api_object_handlers.go)**:
1. Log retrieved entry chunks - shows SseType and metadata after retrieval
2. Log detected SSE type result

This will reveal at which point SSE chunk metadata is lost:
- If finalParts have SSE metadata but versionEntry.Chunks don't → mkFile bug
- If versionEntry.Chunks have SSE metadata but retrieved chunks don't → storage/retrieval bug
- If chunks never have SSE metadata → multipart completion SSE processing bug

Expected to show chunks with SseType=NONE during retrieval even though
they were created with proper SseType during multipart completion.

weed/s3api/filer_multipart.go

@@ -319,7 +319,15 @@ func (s3a *S3ApiServer) completeMultipartUpload(r *http.Request, input *s3.Compl
 		versionDir := dirName + "/" + entryName + s3_constants.VersionsFolder
 
 		// Move the completed object to the versions directory
+		glog.V(0).Infof("completeMultipartUpload: Creating version with %d finalParts chunks", len(finalParts))
+		for i, chunk := range finalParts {
+			glog.V(0).Infof("completeMultipartUpload: finalParts[%d] - SseType=%v, hasMetadata=%v", i, chunk.SseType, len(chunk.SseMetadata) > 0)
+		}
 		err = s3a.mkFile(versionDir, versionFileName, finalParts, func(versionEntry *filer_pb.Entry) {
+			glog.V(0).Infof("completeMultipartUpload: mkFile callback - entry has %d chunks", len(versionEntry.Chunks))
+			for i, chunk := range versionEntry.Chunks {
+				glog.V(0).Infof("completeMultipartUpload: versionEntry.Chunks[%d] - SseType=%v, hasMetadata=%v", i, chunk.SseType, len(chunk.SseMetadata) > 0)
+			}
 			if versionEntry.Extended == nil {
 				versionEntry.Extended = make(map[string][]byte)
 			}
@@ -380,6 +388,7 @@ func (s3a *S3ApiServer) completeMultipartUpload(r *http.Request, input *s3.Compl
 			glog.Errorf("completeMultipartUpload: failed to create version %s: %v", versionId, err)
 			return nil, s3err.ErrInternalError
 		}
+		glog.V(0).Infof("completeMultipartUpload: Successfully created version %s", versionId)
 
 		// Update the .versions directory metadata to indicate this is the latest version
 		err = s3a.updateLatestVersionInDirectory(*input.Bucket, *input.Key, versionId, versionFileName)

weed/s3api/s3api_object_handlers.go

@@ -1342,7 +1342,12 @@ func (s3a *S3ApiServer) HeadObjectHandler(w http.ResponseWriter, r *http.Request
 	}
 
 	// Detect and handle SSE
+	glog.V(0).Infof("GetObjectHandler: Retrieved entry for %s%s - %d chunks", bucket, object, len(objectEntryForSSE.Chunks))
+	for i, chunk := range objectEntryForSSE.Chunks {
+		glog.V(0).Infof("GetObjectHandler: Retrieved chunk[%d] - SseType=%v, hasMetadata=%v, FileId=%s", i, chunk.SseType, len(chunk.SseMetadata) > 0, chunk.FileId)
+	}
 	sseType := s3a.detectPrimarySSEType(objectEntryForSSE)
+	glog.V(0).Infof("GetObjectHandler: Detected SSE type: %s", sseType)
 	if sseType != "" && sseType != "None" {
 		// Validate SSE headers for encrypted objects
 		switch sseType {