Reject branded/generic share images; hero prefers a clean illustrated story

- og:image enrichment now skips branded/generic share images (BBC 'branded_news'
  with its burned-in logo, NPR 'facebook-default', etc.) and keeps the first
  real article image — so no competitor logo lands on our hero. Cleared the few
  already-stored branded URLs so they re-enrich.
- Hero selection now prefers a gentle + readable story that also HAS a (clean)
  image, falling back to gentle-readable, then gentle. The lead is visual when
  possible, typographic otherwise — never branded.

(The '7 cards' report was a stale browser cache: the brief stores 7 and the
built JS requests 7; a hard refresh shows all seven.)

Tests: branded/generic image rejection (87 total).

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

goodnews/api.py

@@ -58,13 +58,18 @@ def get_conn():
 
 
 def _pick_lead(items: list[dict]) -> list[dict]:
-    """Lead with a gentle, readable story when possible.
+    """Lead with a gentle, readable, ideally illustrated story.
 
-    Tries gentle-and-readable first, then gentle, then leaves the order alone.
-    Charged or paywalled stories still appear in the set — they just don't lead.
+    Preference order: gentle + readable + has an image, then gentle + readable,
+    then gentle, then leave the order alone. Charged/paywalled/imageless stories
+    still appear in the set — they just don't lead.
     """
+    def gentle(a: dict) -> bool:
+        return safe_to_lead(a) and not is_paywalled(a.get("canonical_url"))
+
     for ok in (
-        lambda a: safe_to_lead(a) and not is_paywalled(a.get("canonical_url")),
+        lambda a: gentle(a) and bool(a.get("image_url")),
+        gentle,
         safe_to_lead,
     ):
         for i, a in enumerate(items):