feat(cloud): 115/夸克网盘 providers with cookie + QR login and 302 playback

Add a pluggable cloud-disk subsystem (internal/service/cloud) exposing remote
files as playable media via HTTP 302 redirects, so the host never transcodes
nor (by default) streams the bytes:

- quark (夸克网盘): cookie auth, directory listing + download_url resolution.
- cloud115 (115 网盘): cookie auth + QR-code login flow (token/poll/exchange);
  pickcode → CDN URL resolved for 302 offload.
- StorageConfigService gains cloud types, Ping() probes, List/Resolve/Import.
- New endpoints: admin /cloud/:type/{list,import,qr/start,qr/poll} and authed
  /cloud/play/:type (302 redirect, or reverse-proxy when the link needs auth
  headers). Imported files become Media rows with STRMURL → the play endpoint.
- Frontend: 115网盘/夸克网盘 tabs with cookie input, 115 QR-code login, a cloud
  file browser and one-click 302 import.

Providers are exercised against httptest mock servers (list/resolve/QR state
machine). Live login + playback require a real cloud account.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

internal/handler/handler.go

@@ -94,6 +94,10 @@ func Register(r *gin.Engine, cfg *config.Config, log *zap.Logger, svc *service.C
 			authed.GET("/hls/:id/:seg", hlsSegmentHandler(svc))
 			authed.DELETE("/hls/:id", stopTranscodeHandler(svc))
 
+			// Cloud-disk 302 playback redirect (resolves a fresh direct link).
+			authed.GET("/cloud/play/:type", cloudPlayHandler(svc))
+			authed.HEAD("/cloud/play/:type", cloudPlayHandler(svc))
+
 			// Image proxy (URL passed as ?url=...).
 			authed.GET("/img", imageProxyHandler(svc))
 
@@ -305,12 +309,18 @@ func Register(r *gin.Engine, cfg *config.Config, log *zap.Logger, svc *service.C
 			admin.PUT("/users/:id/permissions", updateUserPermissionsHandler(svc))
 			admin.POST("/users/:id/permissions/reset", resetUserPermissionsHandler(svc))
 
-			// Storage configs (Alist / S3 / WebDAV).
+			// Storage configs (Alist / S3 / WebDAV / 网盘).
 			admin.GET("/storage/status", listStorageConfigsHandler(svc))
 			admin.GET("/storage/:type", getStorageConfigHandler(svc))
 			admin.PUT("/storage/:type", saveStorageConfigHandler(svc))
 			admin.POST("/storage/:type/test", testStorageConfigHandler(svc))
 
+			// Cloud disk (115 / 夸克) browsing, QR login and 302 import.
+			admin.GET("/cloud/:type/list", cloudListHandler(svc))
+			admin.POST("/cloud/:type/import", cloudImportHandler(svc))
+			admin.POST("/cloud/:type/qr/start", cloud115QRStartHandler(svc))
+			admin.POST("/cloud/:type/qr/poll", cloud115QRPollHandler(svc))
+
 			// Download client CRUD.
 			admin.GET("/download/clients", listDownloadClientsHandler(svc))
 			admin.POST("/download/clients", createDownloadClientHandler(svc))