fix(files): review round 1, the page — honest states, the keyboard, the tray's words

- A library past the list's cap is searched and sorted on the server; the count says "the newest".
- Each folder and each search opens on its first page (DataTable pageScope, useCardPager scope).
- A file dropped where the page takes none never reaches the browser (which would unload the app).
- The viewer's arrows wait while a layer opened from it is on top, and scroll a wide text line;
  a text shows its first 5000 lines and says where the rest is.
- Confirms name the file (no more "your downloads"); the asking menu rows end in "…".
- The tray names a running step beside its bar, shows a pause mark for paused work, polls slowly
  while only paused work waits, and forgets a finished file that was deleted.
- An unchanged rename sends nothing; a paste opens the download dialog only with nothing on top;
  the link box never replaces what was typed.
- Honest states: folders that failed to load, a file no longer there, the storage figure; the rail
  says "nothing downloaded" only when there is nothing.
- Focus after deleting the open folder and when the format form opens; the format name's label.
- ui/Meter (one danger line for both quota bars) and ui/RenameField in the platform layer.
- Copy fixes, stale comments and the speculative hub key; a contract test for the list's
  parameters; e2e: the Files page and the paste intake.

frontend/src/components/ProfileEditor.tsx

@@ -1,4 +1,4 @@
-import { useState } from "react";
+import { useEffect, useId, useRef, useState } from "react";
 import { qk } from "../lib/queryKeys";
 import { useTranslation } from "react-i18next";
 import type { TFunction } from "i18next";
@@ -93,6 +93,14 @@ export function DownloadFormats() {
   const [name, setName] = useState("");
   const [spec, setSpec] = useState<DownloadSpec>(BLANK);
   const [formOpen, setFormOpen] = useState(false);
+  // Opening the form (New, Edit, Duplicate) puts the keyboard in its name: the form opens away from
+  // the control that asked for it, and "New format" is replaced by it.
+  const [opened, setOpened] = useState(0);
+  const nameField = useRef<HTMLInputElement>(null);
+  const nameId = useId();
+  useEffect(() => {
+    if (opened) nameField.current?.focus();
+  }, [opened]);
 
   const invalidate = () => void qc.invalidateQueries({ queryKey: qk.downloadProfiles() });
   const startNew = () => {
@@ -100,12 +108,14 @@ export function DownloadFormats() {
     setName("");
     setSpec(BLANK);
     setFormOpen(true);
+    setOpened((n) => n + 1);
   };
   const startEdit = (p: DownloadProfile) => {
     setEditing(p);
     setName(p.name);
     setSpec({ ...BLANK, ...p.spec });
     setFormOpen(true);
+    setOpened((n) => n + 1);
   };
   // A new format from an existing one: its settings, and a name of its own to give.
   const startCopy = (p: DownloadProfile) => {
@@ -113,6 +123,7 @@ export function DownloadFormats() {
     setName("");
     setSpec({ ...BLANK, ...p.spec });
     setFormOpen(true);
+    setOpened((n) => n + 1);
   };
 
   const save = useMutation({
@@ -261,8 +272,12 @@ export function DownloadFormats() {
       ) : (
         <div className="rounded-xl border border-border p-4 space-y-3">
           <div>
-            <label className="block text-sm font-medium mb-1">{t("downloads.profiles.name")}</label>
+            <label htmlFor={nameId} className="block text-sm font-medium mb-1">
+              {t("downloads.profiles.name")}
+            </label>
             <Input
+              id={nameId}
+              ref={nameField}
               className="w-full"
               value={name}
               onChange={(e) => setName(e.target.value)}