fix(files): an upload is said once in any order, copy buttons speak, a link list that failed says so

- The queue holds an upload it sees land done while this tab's upload still waits for its answer, so
  the dialog's notice is the only one whichever comes first; another device's upload follows after.
- One `useCopyFeedback` for every Copy beside a value (token, share link, set-password link): Copied
  for a moment, a notice a screen reader hears, a warning when the clipboard refuses; the token
  dialog's two Copy buttons are named by what they copy.
- The share dialog's link list shows loading, and a load error with Retry, never "no links" — and no
  New link beside a list it has not seen.
- The settings texts say that signing out elsewhere or a password change revokes the API tokens.
- DESIGN.md logs the folder-link decisions; the design lab keeps only the chosen renderings of the
  Links, Tokens and Files rounds.

frontend/src/lib/downloadQueue.dom.test.ts

@@ -7,15 +7,18 @@ import type { QueueJob } from "./api";
 import {
   clearFinished,
   forgetFinished,
-  noteAnnounced,
   noteQueue,
   resetQueueWatch,
   takeUnannounced,
+  uploadEnded,
+  uploadStarted,
   useFinished,
 } from "./downloadQueue";
 import { renderHook } from "@testing-library/react";
 
 const job = (id: number, status: string) => ({ id, status }) as unknown as QueueJob;
+const upload = (id: number) =>
+  ({ id, status: "done", source_kind: "upload" }) as unknown as QueueJob;
 const finishedIds = () => renderHook(() => useFinished()).result.current.map((j) => j.id);
 
 beforeEach(resetQueueWatch);
@@ -44,12 +47,39 @@ describe("downloadQueue · a finish", () => {
 
   it("a finish its own action announced is kept for the tray but not announced again", () => {
     noteQueue([]);
-    noteAnnounced(7); // an upload, done in the answer that made it
-    noteQueue([job(7, "done"), job(8, "done")]);
+    uploadStarted();
+    uploadEnded(7); // an upload, done in the answer that made it
+    noteQueue([upload(7), job(8, "done")]);
     expect(takeUnannounced().map((j) => j.id)).toEqual([8]);
     expect(finishedIds()).toEqual([7, 8]);
   });
 
+  it("an upload the queue sees done before its own answer arrives is still said once, by it", () => {
+    noteQueue([]);
+    uploadStarted();
+    noteQueue([upload(7)]); // the server committed it; the answer is still on its way
+    expect(takeUnannounced()).toEqual([]);
+    uploadEnded(7);
+    expect(takeUnannounced()).toEqual([]);
+    expect(finishedIds()).toEqual([7]);
+  });
+
+  it("another device's upload landing meanwhile is announced once this tab's upload answers", () => {
+    noteQueue([]);
+    uploadStarted();
+    noteQueue([upload(7), upload(9)]);
+    uploadEnded(7);
+    expect(takeUnannounced().map((j) => j.id)).toEqual([9]);
+  });
+
+  it("an upload that failed announced nothing: what landed meanwhile is announced", () => {
+    noteQueue([]);
+    uploadStarted();
+    noteQueue([upload(9)]);
+    uploadEnded(null);
+    expect(takeUnannounced().map((j) => j.id)).toEqual([9]);
+  });
+
   it("a failure is not a finish; closing the tray forgets what finished", () => {
     noteQueue([job(1, "running"), job(2, "running")]);
     noteQueue([job(1, "error"), job(2, "done")]);