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/LinkBox.tsx

@@ -41,7 +41,9 @@ export function LinkBox({ className }: { className?: string }) {
   const paste = async (force: boolean) => {
     if (!force && url.trim()) return;
     const link = asDownloadLink(await clipboardText());
-    if (link) setUrl(link);
+    // Asked again once the read is back: it can wait on a permission prompt, and what was typed
+    // meanwhile is the reader's.
+    if (link) setUrl((typed) => (force || !typed.trim() ? link : typed));
   };
 
   // The palette's "Download from link…" (lib/downloadIntake): the request wakes this effect, the