feat(files): folders managed in place, a grid per folder, drop to upload, open on one file

- Own folders are made, renamed and deleted from the rail (right click, long press,
  Shift+F10) or the "…" beside an open folder's name; any folder's retention is a
  submenu (7/30/90 days, until deleted). Deleting confirms where its files go.
- List or grid per folder, sharing one sort; the grid is the one media card.
- A file dropped anywhere on the page opens Upload with it, bound for the folder
  on screen.
- A link (?item=) or the upload notice opens Files on the file: its page turned
  to, the keyboard on it, a ring round it.
- An in-place name field left by Enter or Escape hands the focus back to what
  replaced it (the row, the entry, the "…") instead of dropping it on <body>.
- The table's saved page size is per account.

frontend/src/components/UploadDialog.tsx

@@ -11,6 +11,8 @@ import { notifyActionError } from "../lib/actionErrors";
 import { invalidateDownloads } from "../lib/downloads";
 import { notify } from "../lib/notifications";
 import { navigateTo } from "../lib/nav";
+import type { DownloadJob } from "../lib/api";
+import { useFilesActions } from "./filesContext";
 import { formatBytes } from "../lib/format";
 import { DISPLAY_NAME_MAX } from "../lib/api/downloads";
 import { Pressable } from "./ui/Pressable";
@@ -26,21 +28,21 @@ import { Input } from "./ui/Input";
 // skip the whole dialog.
 const uploadedKey = (status: string) =>
   status === "done" ? "downloads.upload.added" : "downloads.upload.addedConverting";
-// A done file is in Files; one the worker still converts is in the download queue until it is.
-const uploadedPage = (status: string) => (status === "done" ? "files" : "downloads");
-
 export default function UploadDialog({
   folderId = null,
+  initialFile = null,
   onClose,
 }: {
   /** The library folder the file goes into (an own folder, or the Uploads folder); null = Uploads. */
   folderId?: number | null;
+  /** A file already chosen — dropped on the Files page — so the dialog opens ready to send it. */
+  initialFile?: File | null;
   onClose: () => void;
 }) {
   const { t, i18n } = useTranslation();
   const lang = i18n.language;
   const qc = useQueryClient();
-  const [file, setFile] = useState<File | null>(null);
+  const [file, setFile] = useState<File | null>(initialFile);
   const [name, setName] = useState("");
   const [dragOver, setDragOver] = useState(false);
   const [pct, setPct] = useState<number | null>(null); // null = idle; 0–100 while uploading
@@ -65,6 +67,13 @@ export default function UploadDialog({
   // silent to a screen reader. `SetupWizard` and `Welcome` both key their alerts for the
   // same reason, and `formAlerts.dom.test.tsx` is the test that exists because of it.
   const [pickSeq, setPickSeq] = useState(0);
+  const { openFile } = useFilesActions();
+  // A done file is in Files, opened on it; one the worker still converts is in the download queue
+  // until it is.
+  const openUploaded = (job: DownloadJob) => {
+    if (job.status === "done") openFile(job.id, job.folder_id ?? null);
+    else navigateTo("downloads");
+  };
   const pick_ = (f: File) => {
     setFile(f);
     setName("");
@@ -101,7 +110,7 @@ export default function UploadDialog({
         message: t(uploadedKey(job.status)),
         action: {
           label: t("downloads.dialog.view"),
-          onClick: () => navigateTo(uploadedPage(job.status)),
+          onClick: () => openUploaded(job),
         },
       });
       onClose();