fix(downloads): an upload's cancel, progress, failure and notice speak of an upload

- Cancelling an upload asks "Delete upload?" and says the uploaded file is
  removed from the server with it.
- The phone-safe conversion's real ffmpeg % shows as a bar ("Converting for
  phones"), not an indeterminate pulse.
- A failed upload is titled "The upload isn't ready", with its own reasons
  (convert_failed, retryable; upload_missing) instead of download copy.
- The inbox says "Upload ready to share" for a converted upload.

frontend/src/components/downloadRow.dom.test.tsx

@@ -292,3 +292,27 @@ describe("DownloadRow · no picture", () => {
     expect(container.querySelector("svg.lucide-film")).not.toBeNull();
   });
 });
+
+// The phone-safe conversion reports ffmpeg's real progress, so it gets the % bar a download has;
+// a yt-dlp post-step reports none and keeps the pulse.
+describe("DownloadRow · a running conversion", () => {
+  const running = (phase: string): DownloadJob => ({
+    ...baseJob,
+    status: "running",
+    progress: 40,
+    phase,
+  });
+
+  it("shows its phase and its %", () => {
+    const { container } = render(<DownloadRow job={running("converting")} />);
+    expect(screen.getByText("downloads.phase.converting")).toBeTruthy();
+    expect(screen.getByText("40%")).toBeTruthy();
+    expect(container.querySelector(".animate-pulse")).toBeNull();
+  });
+
+  it("a post-step with no % keeps the pulse", () => {
+    const { container } = render(<DownloadRow job={running("merging")} />);
+    expect(screen.queryByText("40%")).toBeNull();
+    expect(container.querySelector(".animate-pulse")).not.toBeNull();
+  });
+});