Upload progress: Redis-backed store + flushed SSE + client fallback

The previous in-memory _progress dict + polling SSE handler had a 30s silent
tail after completion. HTTP/2 framing in the proxy chain (Traefik) buffered
the small chunks until the stream closed, so when a transient blip caused
EventSource to reconnect, the server returned 404 and the UI stuck on the
"מתחיל…" placeholder forever. Reproduced live: 445 bytes withheld 31s.

Changes:
  • web/progress_store.py — ProgressStore wraps Redis with TTL (5m), atomic
    GETDEL, dict-like API. Best-effort: Redis errors are logged and swallowed
    so observability outages don't break uploads.
  • web/app.py — _progress is now Redis-backed; every set/get/active/pop is
    awaited. SSE handler emits a heartbeat each tick (forces HTTP/2 flush),
    drops the 30s post-completion sleep, and returns a terminal
    {"status":"unknown"} payload instead of 404 when the task is gone — so
    EventSource closes cleanly instead of reconnect-looping. New _SSE_HEADERS
    set X-Accel-Buffering: no.
  • web-ui useProgress(taskId, caseNumber) — 10s fallback that invalidates
    the case detail if no SSE message arrived; treats "unknown" as terminal
    and triggers a refetch from the source of truth.
  • upload-sheet wires caseNumber through and renders "unknown" as completed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web-ui/src/components/documents/upload-sheet.tsx

@@ -43,6 +43,7 @@ function statusLabel(event: ProgressEvent | null): string {
   if (event.status === "processing")
     return event.step ? `בעיבוד · ${event.step}` : "בעיבוד";
   if (event.status === "completed") return "הושלם";
+  if (event.status === "unknown") return "הושלם";
   if (event.status === "failed") return event.error ?? "נכשל";
   return event.status;
 }
@@ -52,15 +53,16 @@ function progressPercent(event: ProgressEvent | null): number {
   if (event.status === "queued") return 10;
   if (event.status === "processing") return 55;
   if (event.status === "completed") return 100;
+  if (event.status === "unknown") return 100;
   if (event.status === "failed") return 100;
   return 25;
 }
 
-function UploadRowView({ row }: { row: UploadRow }) {
-  const progress = useProgress(row.taskId);
+function UploadRowView({ row, caseNumber }: { row: UploadRow; caseNumber: string }) {
+  const progress = useProgress(row.taskId, caseNumber);
   const pct = row.error ? 100 : progressPercent(progress);
   const failed = row.error || progress?.status === "failed";
-  const done = progress?.status === "completed";
+  const done = progress?.status === "completed" || progress?.status === "unknown";
 
   return (
     <li className="rounded-lg border border-rule bg-parchment/40 px-4 py-3 space-y-2">
@@ -197,7 +199,7 @@ export function UploadSheet({ caseNumber }: { caseNumber: string }) {
           {rows.length > 0 && (
             <ul className="space-y-2">
               {rows.map((row) => (
-                <UploadRowView key={row.id} row={row} />
+                <UploadRowView key={row.id} row={row} caseNumber={caseNumber} />
               ))}
             </ul>
           )}