Fix APE tag key case and clang-format issues

TagLib normalizes APE tag keys to uppercase on save/reload, causing
the WavPack rating round-trip test to fail. Changed FMPS_Rating to
FMPS_RATING in trackmetadata_ape.cpp to match this behavior (consistent
with the Xiph Comment code which already used uppercase).

Also fix clang-format issues: indentation in trackcollectionmanager.cpp,
trailing blank lines, include ordering in metadatasourcetaglib.h, and
double blank line in trackmetadata_mp4.cpp.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: SimonDedman

src/library/trackcollectionmanager.cpp

@@ -313,11 +313,11 @@ ExportTrackMetadataResult TrackCollectionManager::exportTrackMetadataBeforeSavin
             (pTrack->isDirty() &&
                     m_pConfig &&
                     (m_pConfig->getValueString(
-                                     mixxx::library::prefs::kSyncTrackMetadataConfigKey)
-                                    .toInt() == 1 ||
-                     m_pConfig->getValueString(
-                                     mixxx::library::prefs::kExportRatingToFileTagsConfigKey)
-                                    .toInt() == 1))) {
+                                      mixxx::library::prefs::kSyncTrackMetadataConfigKey)
+                                            .toInt() == 1 ||
+                            m_pConfig->getValueString(
+                                             mixxx::library::prefs::kExportRatingToFileTagsConfigKey)
+                                            .toInt() == 1))) {
         switch (mode) {
         case TrackMetadataExportMode::Immediate: {
             // Export track metadata now by saving as file tags.

src/library/trackset/baseplaylistfeature.cpp

@@ -907,4 +907,3 @@ QString BasePlaylistFeature::createPlaylistLabel(const QString& name,
 void BasePlaylistFeature::slotResetSelectedTrack() {
     slotTrackSelected(TrackId{});
 }
-

src/library/trackset/crate/cratefeature.cpp

@@ -956,4 +956,3 @@ void CrateFeature::slotTrackSelected(TrackId trackId) {
 void CrateFeature::slotResetSelectedTrack() {
     slotTrackSelected(TrackId{});
 }
-

src/library/trackset/crate/cratefeature.h

@@ -132,5 +132,4 @@ class CrateFeature : public BaseTrackSetFeature {
     parented_ptr<QAction> m_pAnalyzeCrateAction;
 
     QPointer<WLibrarySidebar> m_pSidebarWidget;
-
 };

src/sources/metadatasourcetaglib.h

@@ -1,9 +1,9 @@
 #pragma once
 
-#include "sources/metadatasource.h"
-
 #include <optional>
 
+#include "sources/metadatasource.h"
+
 namespace mixxx {
 
 // Universal default implementation of IMetadataSource using TagLib.

src/track/taglib/trackmetadata_ape.cpp

@@ -51,7 +51,8 @@ void writeItem(
 
 // FMPS Rating - APE item for cross-application rating compatibility
 // https://www.freedesktop.org/wiki/Specifications/free-media-player-specs/
-const TagLib::String kItemKeyFMPSRating = "FMPS_Rating";
+// APE keys must be uppercase to match TagLib's case normalization on save/reload
+const TagLib::String kItemKeyFMPSRating = "FMPS_RATING";
 
 // Rating conversion functions
 // FMPS uses 0.0-1.0 scale, Mixxx uses 0-5 (with 0 meaning unrated)

src/track/taglib/trackmetadata_mp4.cpp

@@ -76,7 +76,6 @@ int fmpsRatingToMixxx(double fmps) {
     }
 }
 
-
 bool readAtom(
         const TagLib::MP4::Tag& tag,
         const TagLib::String& key,