fix(user-flow): close offline-queue, export, session, ban & realtime gaps

Comprehensive user-flow review across guest/host/admin roles, then fixes with
e2e regression guards. Highlights:

- Offline upload queue auto-resumes on reconnect: network errors keep items
  pending (not error), 4xx are terminal (no infinite retry), quota exhaustion
  returns a distinct 413; queue cap + dedup.
- Export lifecycle: release atomically locks uploads; reopen invalidates and
  re-release regenerates the keepsake; workers claim their job atomically so a
  reopen->re-release can't corrupt the ZIP; startup re-spawns interrupted
  exports.
- Sessions slide on activity (no 30-day cliff); JWT expiry deferred to the
  revocable session row; sign-out-everywhere + revoke-on-PIN-reset.
- Ban always hides content (v_feed / find_visible_media / export filter
  is_banned) but stays a read-only ban per USER_JOURNEYS §10 — sessions are
  not revoked, read access + keepsake download preserved.
- Realtime: server-clock SSE delta cursor; event-closed/opened drive the UI
  live; feed_delta rate-limited; like returns {liked, like_count} to fix
  multi-device drift; lightbox live comments; diashow delta backfill.
- Forgotten-PIN in-app request flow; simultaneous same-name join returns 409;
  quota increment is transactional; operator floor.

Adds e2e/specs/10-flow-review/ (offline resume, export integrity, deterministic
anti-race guard) and updates existing specs for the new contracts.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/LightboxModal.svelte

@@ -58,9 +58,21 @@
 		} catch { /* ignore */ }
 	});
 
+	// Pull in a comment posted from another device on the CURRENTLY-open upload, so the
+	// open list matches the count. The `new-comment` broadcast carries only the count (not
+	// the body), so refetch — skipped when it's for a different upload, and the dedupe
+	// below makes our own just-posted optimistic comment a no-op.
+	const unsubNewComment = onSseEvent('new-comment', (data) => {
+		try {
+			const { upload_id } = JSON.parse(data) as { upload_id: string };
+			if (upload_id === upload.id) void loadComments(upload.id);
+		} catch { /* ignore */ }
+	});
+
 	onDestroy(() => {
 		if (burstTimer) clearTimeout(burstTimer);
 		unsubCommentDeleted();
+		unsubNewComment();
 	});
 
 	// Only refetch when a *different* upload is shown. The feed reassigns the