feat(files): W5-A2 move/copy via planImport, organize overrides, delete records, download

- /files/move|copy go through planImport's new `transfer` variant (keep names, directory
  expanded to per-file plan) → organization_record + verifyAndImport/executeRecord: per-file
  ledger resumable, fsproxy, cross-volume directory move = per-file copy→verify→delete then
  remove empty source dirs; shared plan store + plan_stale; asset_location follows per file,
  path_binding revised when a whole directory moved (finalizeTransfer); request waits up to
  FILES_TRANSFER_WAIT_SEC, else executed.pending
- /files/organize per-item overrides take effect: season/episodes (domain planOrganize
  overrides), contentUnitId coverage, targetDir (no binding), operation, slotId (satisfied
  after verify); warnings only for inapplicable overrides
- delete/trash/restore write organization_record (action trash|delete|restore, file-level
  results; migration 0026)
- GET /files/download (admin session, nfo/subtitle/image, size cap, streamed, audited)
- GET /files/records?ids|planIds for the organize page
- fs race errors map to 503/404/403/400 instead of 500
- runbook updated

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/contracts/src/api.ts

@@ -1177,6 +1177,22 @@ export const Api = {
       body: files.FilesProbeRequest,
       response: files.FilesProbeResult,
     }),
+    download: ep({
+      method: "get",
+      path: "/files/download",
+      scope: "admin",
+      summary: "下载小文件(nfo/字幕/图片,≤20 MiB;流式;服务端另要求 admin 控制台会话;审计)",
+      query: files.FilesDownloadQuery,
+      response: files.FilesDownloadResponse,
+    }),
+    records: ep({
+      method: "get",
+      path: "/files/records",
+      scope: "organize.read",
+      summary: "按整理记录 id 或 planId 回查整理记录(整理页预填)",
+      query: files.FilesRecordsQuery,
+      response: files.FilesRecordsResult,
+    }),
   },
 
   // ── 能力 ──