refactor(media): consolidate upload/edit/download into MediaService

Merge UploadService, EditService, JobOrchestrationService, and
DownloadService into a single MediaService with a unified Job lifecycle
(READY → PROCESSING → SUCCEEDED/FAILED via JobState enum).

- Add MediaController (/api/v1/media) exposing compress, save, and clip
- Add JobController (/api/v1/job) for status polling and file download
- Move clip/thumbnail download into ClipController (/{id}/media, /{id}/thumbnail)
- Move stream saveSection/clip from StreamService into MediaService
- Simplify Job DTO: remove dual ClipOptions/files, add ProgressTracker and download file
- Refactor JobRegistryService.add() → generateJob() to co-locate creation and registration
- Wire FFmpeg out_time_ms progress parsing into StreamActionsService via CommandRunner
- Rename GET /api/v1/auth/user → GET /api/v1/user/me
- Delete DownloadController, MetadataController, UploadController

src/main/java/com/ddf/vodsystem/controllers/ClipController.java

@@ -5,6 +5,10 @@ import com.ddf.vodsystem.dto.APIResponse;
 import com.ddf.vodsystem.controllers.dto.ClipUpdateRequest;
 import com.ddf.vodsystem.entities.Clip;
 import com.ddf.vodsystem.services.ClipService;
+import org.springframework.core.io.Resource;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.MediaTypeFactory;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
@@ -16,6 +20,7 @@ import java.util.Optional;
 public class ClipController {
     private final ClipService clipService;
     private static final String SUCCESS = "success";
+    private static final String FILENAME_HEADER = "inline; filename=\"%s\"";
 
     public ClipController(ClipService clipService) {
         this.clipService = clipService;
@@ -79,6 +84,34 @@ public class ClipController {
         );
     }
 
+    @GetMapping("/{id}/media")
+    public ResponseEntity<Resource> downloadClip(@PathVariable Long id) {
+        Resource resource = clipService.downloadClip(id);
+
+        if (resource == null || !resource.exists()) {
+            return ResponseEntity.notFound().build();
+        }
+
+        return ResponseEntity.ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION, String.format(FILENAME_HEADER, resource.getFilename()))
+                .contentType(MediaTypeFactory.getMediaType(resource).orElse(MediaType.APPLICATION_OCTET_STREAM))
+                .body(resource);
+    }
+
+    @GetMapping("/{id}/thumbnail")
+    public ResponseEntity<Resource> downloadThumbnail(@PathVariable Long id) {
+        Resource resource = clipService.downloadThumbnail(id);
+
+        if (resource == null || !resource.exists()) {
+            return ResponseEntity.notFound().build();
+        }
+
+        return ResponseEntity.ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION, String.format(FILENAME_HEADER, resource.getFilename()))
+                .contentType(MediaTypeFactory.getMediaType(resource).orElse(MediaType.APPLICATION_OCTET_STREAM))
+                .body(resource);
+    }
+
     private ClipResponse convertToDTO(Clip clip) {
         return new ClipResponse(
                 clip.getId(),