Correct 29/09 post's Content Type: Carousel, not default Text/Image

LinkedIn's export doesn't distinguish carousel/document posts from
generic Image, so this needed the usual manual override.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app.py

@@ -65,6 +65,7 @@ MANUAL_CONTENT_TYPES = {
     "2026-07-30": "Carousel",
     "2026-08-04": "Carousel",
     "2026-08-06": "Poll",
+    "2026-09-29": "Carousel",
 }
 
 # ── Palette — matched to txdata_project/portal.py's navy/blue design language ──