Images phase 1: attention-triggered og:image coverage

Tie image enrichment to attention (per review): when an article earns a summary
(i.e. a reader reached it), best-effort fetch a real og:image if it lacks one —
never blanket-fetch every ingested article. Adds:

* enrich_article_image() — single-article fetch, leaves existing images alone,
  retries an imageless article only after 7 days, stamps image_checked_at.
* generate_summary() calls it after caching (wrapped; never breaks summaries).
* enrich_summarized_images() + `goodnews enrich-images` CLI — slow background
  backfill of already-summarized, accepted, imageless articles.
* Quality gate: extend the generic-image skip list with data:/tracking-pixel/
  spacer markers (on top of the existing logo/placeholder + unbranded-BBC logic).

This is coverage only; display (editorial rhythm, tile treatment) comes next.

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

goodnews/cli.py

@@ -9,7 +9,7 @@ from .briefs import build_daily_brief, show_brief
 from .db import connect, init_db
 from .localtime import local_today
 from .dedup import DEFAULT_THRESHOLD, DEFAULT_WINDOW_DAYS, dedup as run_dedup
-from .enrich import enrich_brief_images
+from .enrich import enrich_brief_images, enrich_summarized_images
 from .summarize import generate_summary, get_summary
 from .feeds import (
     fetch_feed,
@@ -127,6 +127,11 @@ def main() -> None:
     cycle_parser.add_argument("--base-url", help="OpenAI-compatible base URL for classify")
     cycle_parser.add_argument("--model", help="Local model name for classify")
 
+    enrich_images_parser = subparsers.add_parser(
+        "enrich-images", help="Backfill og:images for already-summarized articles that lack one"
+    )
+    enrich_images_parser.add_argument("--limit", type=int, default=50, help="Max articles to fetch this batch")
+
     dedup_parser = subparsers.add_parser("dedup", help="Cluster near-duplicate stories via local embeddings")
     dedup_parser.add_argument("--threshold", type=float, default=DEFAULT_THRESHOLD, help="Cosine similarity cutoff")
     dedup_parser.add_argument("--window-days", type=int, default=DEFAULT_WINDOW_DAYS)
@@ -266,6 +271,9 @@ def main() -> None:
             print("Dry run only; database was not updated.")
     elif args.command == "cycle":
         run_cycle(conn, args)
+    elif args.command == "enrich-images":
+        found = enrich_summarized_images(conn, limit=args.limit)
+        print(f"enrich-images: {found} new image(s) for summarized articles")
     elif args.command == "dedup":
         init_db(conn)
         client = llm_client_from_args(args)