Squashed commit of the following:

commit f17f943bc149fef1a0ef3f884cf8653e70469ac5
Author: Nik Afiq <nik.afiq98@ymail.com>
Date:   Fri Dec 5 22:33:01 2025 +0900

    Fix JSON tags for Episode struct fields in model.go

backend/internal/core/episode/model.go

@@ -14,13 +14,13 @@ var (
 
 // Episode represents a single show/episode in the system.
 type Episode struct {
-	Id             int
-	EpNum          int
-	EpTitle        string
-	SeasonName     string
-	StartTime      string
-	PlaybackLength string
-	DateCreated    time.Time
+	Id             int       `json:"id"`
+	EpNum          int       `json:"ep_num"`
+	EpTitle        string    `json:"ep_title"`
+	SeasonName     string    `json:"season_name"`
+	StartTime      string    `json:"start_time"`
+	PlaybackLength string    `json:"playback_length"`
+	DateCreated    time.Time `json:"date_created"`
 }
 
 // MoveResult describes what happened during an archive move operation.