Durable image quality: stop trusting feed thumbnails; cycle enriches Latest

Make "no blurry images" sustainable, not a one-off cleanup. RSS feed thumbnails
(~44% were ~90px) were stored at ingest and upscaled to mush, so new articles
would reintroduce them. Now image_url is filled ONLY by the quality-gated
og:image enrichment:

* insert_article no longer stores the feed image (was canonicalize_url(item...)).
* enrich_recent_images(): the cycle fetches a quality og:image for the newest
  accepted, imageless articles each run (bounded), keeping Latest photo-rich.
* Brief + on-open enrichment unchanged.

Net: every stored image is a validated, ≥450px og:image; the rest are clean
placeholders.

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

goodnews/enrich.py

@@ -360,6 +360,32 @@ def enrich_article_image(
     return bool(image)
 
 
+def enrich_recent_images(
+    conn: sqlite3.Connection, fetch=fetch_og_image, limit: int = 40, retry_days: int = 7
+) -> int:
+    """Keep the Latest feed photo-rich: fetch a quality og:image for the newest
+    accepted, non-duplicate articles that lack one. Bounded per run, so it tracks
+    fresh content without blanket-fetching the archive. Returns newly-found count.
+    """
+    rows = conn.execute(
+        """
+        SELECT a.id FROM articles a
+        JOIN article_scores s ON s.article_id = a.id
+        WHERE s.accepted = 1 AND a.duplicate_of IS NULL
+          AND (a.image_url IS NULL OR a.image_url = '')
+          AND (a.image_checked_at IS NULL OR a.image_checked_at < datetime('now', ?))
+        ORDER BY COALESCE(a.published_at, a.discovered_at) DESC
+        LIMIT ?
+        """,
+        (f"-{retry_days} days", limit),
+    ).fetchall()
+    found = 0
+    for row in rows:
+        if enrich_article_image(conn, row["id"], fetch=fetch, retry_days=retry_days):
+            found += 1
+    return found
+
+
 def enrich_summarized_images(
     conn: sqlite3.Connection, fetch=fetch_og_image, limit: int = 50, retry_days: int = 7
 ) -> int: