ADD thumbnail to database (#12)

* ADD thumbnail to database

* ADD thumbnail generation and retrieval functionality

* ADD thumbnail availability check in VideoCard component

* ADD ClipDTO to reduce exposed internals

* REFactor move APIResponse and VideoMetadata to dto package

* REMOVE unused props from VideoCard

* ADD isThumbnailAvailable function

src/main/java/com/ddf/vodsystem/dto/APIResponse.java

@@ -0,0 +1,16 @@
+package com.ddf.vodsystem.dto;
+
+import lombok.Data;
+
+@Data
+public class APIResponse<T> {
+    private String status;
+    private String message;
+    private T data;
+
+    public APIResponse(String status, String message, T data) {
+        this.status = status;
+        this.message = message;
+        this.data = data;
+    }
+}

src/main/java/com/ddf/vodsystem/dto/ClipDTO.java

@@ -0,0 +1,15 @@
+package com.ddf.vodsystem.dto;
+
+import lombok.Data;
+
+import java.time.LocalDateTime;
+
+@Data
+public class ClipDTO {
+    private Long id;
+    private Long userId;
+    private String title;
+    private String description;
+    private Float duration;
+    private LocalDateTime createdAt;
+}

src/main/java/com/ddf/vodsystem/dto/VideoMetadata.java

@@ -0,0 +1,15 @@
+package com.ddf.vodsystem.dto;
+
+import lombok.Data;
+
+@Data
+public class VideoMetadata {
+    private String title;
+    private String description;
+    private Float startPoint;
+    private Float endPoint;
+    private Float fps;
+    private Integer width;
+    private Integer height;
+    private Float fileSize;
+}