Merge develop into feature/50-upload-soundtrack

The API spec is now formatted like before (2-space indents, sorted keys):
develop's spec with the upload paths and types added, so the diff to
develop is only the upload API.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/fakes/ui_tour.gd

@@ -18,7 +18,7 @@ const SONG_INFO: Dictionary = {
 	"SongNo": 0, "Soundtrack": "Chrono Trigger", "SoundtrackUuid": "soundtrack-0",
 	"Song": "Corridors of Time",
 }
-const SYNC_PROGRESS: Dictionary = {"progress": 40, "time_spent": "00:00:02"}
+const SYNC_PROGRESS: Dictionary = {"progress": 40, "time_spent": "00:02"}
 const SYNC_RESULT: Dictionary = {
 	"soundtracks_added": ["Terranigma", "Lufia II"],
 	"soundtracks_re_added": [],
@@ -26,7 +26,7 @@ const SYNC_RESULT: Dictionary = {
 	"soundtracks_changed_content": ["Chrono Trigger"],
 	"soundtracks_removed": ["Old Soundtrack"],
 	"catched_errors": [],
-	"total_time": "00:00:03",
+	"total_time": "00:03",
 }
 
 ## The server's version history, newest first.