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>

web/src/api/storage_config.ts

@@ -1,6 +1,26 @@
 import { api } from './client'
 
-export type StorageType = 'alist' | 's3' | 'webdav'
+export type StorageType = 'alist' | 's3' | 'webdav' | 'cloud115' | 'quark'
+
+export interface CloudEntry {
+  id: string
+  name: string
+  is_dir: boolean
+  size: number
+  pick_code?: string
+}
+
+export interface QRSession {
+  uid: string
+  time: number
+  sign: string
+  qr_image_url: string
+}
+
+export interface QRStatus {
+  state: 'waiting' | 'scanned' | 'confirmed' | 'expired'
+  cookie?: string
+}
 
 export interface StorageConfig {
   id: string
@@ -34,3 +54,24 @@ export const storageAPI = {
       })
       .then((r) => r.data),
 }
+
+// cloudAPI drives 网盘 browsing, QR login and 302 import.
+export const cloudAPI = {
+  list: (type: StorageType, dir = '') =>
+    api
+      .get<{ items: CloudEntry[]; error?: string }>(`/admin/cloud/${type}/list`, {
+        params: { dir },
+      })
+      .then((r) => r.data),
+
+  import: (type: StorageType, ref: string, name: string, size: number) =>
+    api
+      .post(`/admin/cloud/${type}/import`, { ref, name, size })
+      .then((r) => r.data),
+
+  qrStart: (type: StorageType) =>
+    api.post<QRSession>(`/admin/cloud/${type}/qr/start`).then((r) => r.data),
+
+  qrPoll: (type: StorageType, sess: QRSession) =>
+    api.post<QRStatus>(`/admin/cloud/${type}/qr/poll`, sess).then((r) => r.data),
+}